Describe the bug
If I reexport an external library through one file and use the types from that reexported library in another file, it will break with a griffe.exceptions.AliasResolutionError.
This might be a feature requests, but I wasn't sure.

To Reproduce
Given a package called docstring_thing and two files like this:

# b.py
import polars as polars

# a.py
from docstring_thing.b import polars
def my_func(input: polars.LazyFrame) -> polars.LazyFrame:
    """
    Args:
        input: The first parameter.

    Returns:
        The return value.
    """
    pass

mkdocs serve will break with griffe.exceptions.AliasResolutionError: Could not resolve polars

Full output

INFO     -  Building documentation...
INFO     -  Cleaning site directory
ERROR    -  Error building page 'index.md': Could not resolve polars
Traceback (most recent call last):
  File "/home/sras/.cache/pypoetry/virtualenvs/docstring-thing-Gq5GOpo2-py3.10/lib/python3.10/site-packages/mkdocs_autorefs/plugin.py", line 78, in _get_item_url
    return self._url_map[identifier]
KeyError: 'docstring_thing.b.polars.LazyFrame'
During handling of the above exception, another exception occurred:
Traceback (most recent call last):
  File "/home/sras/.cache/pypoetry/virtualenvs/docstring-thing-Gq5GOpo2-py3.10/lib/python3.10/site-packages/griffe/dataclasses.py", line 1111, in _resolve_target
    resolved = self.modules_collection[self.target_path]
  File "/home/sras/.cache/pypoetry/virtualenvs/docstring-thing-Gq5GOpo2-py3.10/lib/python3.10/site-packages/griffe/mixins.py", line 27, in __getitem__
    return self.members[parts[0]]  # type: ignore[attr-defined]
KeyError: 'polars'
The above exception was the direct cause of the following exception:
Traceback (most recent call last):
  File "/home/sras/.cache/pypoetry/virtualenvs/docstring-thing-Gq5GOpo2-py3.10/bin/mkdocs", line 8, in <module>
    sys.exit(cli())
  File "/home/sras/.cache/pypoetry/virtualenvs/docstring-thing-Gq5GOpo2-py3.10/lib/python3.10/site-packages/click/core.py", line 1130, in __call__
    return self.main(*args, **kwargs)
  File "/home/sras/.cache/pypoetry/virtualenvs/docstring-thing-Gq5GOpo2-py3.10/lib/python3.10/site-packages/click/core.py", line 1055, in main
    rv = self.invoke(ctx)
  File "/home/sras/.cache/pypoetry/virtualenvs/docstring-thing-Gq5GOpo2-py3.10/lib/python3.10/site-packages/click/core.py", line 1657, in invoke
    return _process_result(sub_ctx.command.invoke(sub_ctx))
  File "/home/sras/.cache/pypoetry/virtualenvs/docstring-thing-Gq5GOpo2-py3.10/lib/python3.10/site-packages/click/core.py", line 1404, in invoke
    return ctx.invoke(self.callback, **ctx.params)
  File "/home/sras/.cache/pypoetry/virtualenvs/docstring-thing-Gq5GOpo2-py3.10/lib/python3.10/site-packages/click/core.py", line 760, in invoke
    return __callback(*args, **kwargs)
  File "/home/sras/.cache/pypoetry/virtualenvs/docstring-thing-Gq5GOpo2-py3.10/lib/python3.10/site-packages/mkdocs/__main__.py", line 234, in serve_command
    serve.serve(dev_addr=dev_addr, livereload=livereload, watch=watch, **kwargs)
  File "/home/sras/.cache/pypoetry/virtualenvs/docstring-thing-Gq5GOpo2-py3.10/lib/python3.10/site-packages/mkdocs/commands/serve.py", line 83, in serve
    builder(config)
  File "/home/sras/.cache/pypoetry/virtualenvs/docstring-thing-Gq5GOpo2-py3.10/lib/python3.10/site-packages/mkdocs/commands/serve.py", line 76, in builder
    build(config, live_server=live_server, dirty=dirty)
  File "/home/sras/.cache/pypoetry/virtualenvs/docstring-thing-Gq5GOpo2-py3.10/lib/python3.10/site-packages/mkdocs/commands/build.py", line 329, in build
    _build_page(file.page, config, doc_files, nav, env, dirty)
  File "/home/sras/.cache/pypoetry/virtualenvs/docstring-thing-Gq5GOpo2-py3.10/lib/python3.10/site-packages/mkdocs/commands/build.py", line 234, in _build_page
    output = config.plugins.run_event('post_page', output, page=page, config=config)
  File "/home/sras/.cache/pypoetry/virtualenvs/docstring-thing-Gq5GOpo2-py3.10/lib/python3.10/site-packages/mkdocs/plugins.py", line 520, in run_event
    result = method(item, **kwargs)
  File "/home/sras/.cache/pypoetry/virtualenvs/docstring-thing-Gq5GOpo2-py3.10/lib/python3.10/site-packages/mkdocs_autorefs/plugin.py", line 205, in on_post_page
    fixed_output, unmapped = fix_refs(output, url_mapper)
  File "/home/sras/.cache/pypoetry/virtualenvs/docstring-thing-Gq5GOpo2-py3.10/lib/python3.10/site-packages/mkdocs_autorefs/references.py", line 191, in fix_refs
    html = AUTO_REF_RE.sub(fix_ref(url_mapper, unmapped), html)
  File "/home/sras/.cache/pypoetry/virtualenvs/docstring-thing-Gq5GOpo2-py3.10/lib/python3.10/site-packages/mkdocs_autorefs/references.py", line 157, in inner
    url = url_mapper(unescape(identifier))
  File "/home/sras/.cache/pypoetry/virtualenvs/docstring-thing-Gq5GOpo2-py3.10/lib/python3.10/site-packages/mkdocs_autorefs/plugin.py", line 107, in get_item_url
    url = self._get_item_url(identifier, fallback)
  File "/home/sras/.cache/pypoetry/virtualenvs/docstring-thing-Gq5GOpo2-py3.10/lib/python3.10/site-packages/mkdocs_autorefs/plugin.py", line 83, in _get_item_url
    new_identifiers = fallback(identifier)
  File "/home/sras/.cache/pypoetry/virtualenvs/docstring-thing-Gq5GOpo2-py3.10/lib/python3.10/site-packages/mkdocstrings/handlers/base.py", line 531, in get_anchors
    anchors = handler.get_anchors(handler.collect(identifier, fallback_config))
  File "/home/sras/.cache/pypoetry/virtualenvs/docstring-thing-Gq5GOpo2-py3.10/lib/python3.10/site-packages/mkdocstrings_handlers/python/handler.py", line 223, in collect
    doc_object = self._modules_collection[identifier]
  File "/home/sras/.cache/pypoetry/virtualenvs/docstring-thing-Gq5GOpo2-py3.10/lib/python3.10/site-packages/griffe/mixins.py", line 28, in __getitem__
    return self.members[parts[0]][parts[1:]]  # type: ignore[attr-defined]
  File "/home/sras/.cache/pypoetry/virtualenvs/docstring-thing-Gq5GOpo2-py3.10/lib/python3.10/site-packages/griffe/mixins.py", line 28, in __getitem__
    return self.members[parts[0]][parts[1:]]  # type: ignore[attr-defined]
  File "/home/sras/.cache/pypoetry/virtualenvs/docstring-thing-Gq5GOpo2-py3.10/lib/python3.10/site-packages/griffe/mixins.py", line 28, in __getitem__
    return self.members[parts[0]][parts[1:]]  # type: ignore[attr-defined]
  File "/home/sras/.cache/pypoetry/virtualenvs/docstring-thing-Gq5GOpo2-py3.10/lib/python3.10/site-packages/griffe/dataclasses.py", line 817, in __getitem__
    return self.target[key]
  File "/home/sras/.cache/pypoetry/virtualenvs/docstring-thing-Gq5GOpo2-py3.10/lib/python3.10/site-packages/griffe/dataclasses.py", line 1078, in target
    self.resolve_target()
  File "/home/sras/.cache/pypoetry/virtualenvs/docstring-thing-Gq5GOpo2-py3.10/lib/python3.10/site-packages/griffe/dataclasses.py", line 1105, in resolve_target
    self._resolve_target()
  File "/home/sras/.cache/pypoetry/virtualenvs/docstring-thing-Gq5GOpo2-py3.10/lib/python3.10/site-packages/griffe/dataclasses.py", line 1113, in _resolve_target
    raise AliasResolutionError(self.target_path) from error
griffe.exceptions.AliasResolutionError: Could not resolve polars

Expected behavior
I would want it not to break. Linking to the actual library class is not needed.
Screenshots

System (please complete the following information):

mkdocstrings-python version: 0.20
Python version: 3.10
OS: Ubuntu 22.04.1 LTS (in WSL)

Additional context
I'm reexporting it because I need to register extra functions. I'm using a linter to force all polars imports to go through that file to be sure that the functions are registered.