Contributor

This adds support for attributes in generated Action traits as discussed here. This closes #6592.

• I've also tidied up a few CI-related things see Bump GitHub actions #6604 instead.
• Added parameters to the attributes so IDEs don't complain about parameters being there when they think there shouldn't be see Provide typed signatures for attributes #6600 instead.

TODO

• Handle parameter attributes.
• Tests for parameter attributes.
• Update docs, including note about named parameters (in my branch).