Restructure github_toolsets_permissions.json (v2.2 -> v2.3) to match the
current github/github-mcp-server main tool registration:
- Remove the 'search' toolset; redistribute search tools:
  search_code/search_commits/search_repositories -> repos,
  search_orgs -> orgs, search_users -> users
- Remove semantic_issues_search / semantic_issue_similarity_search (gone upstream)
- Remove the 'experiments' toolset (dynamic-toolset tools removed upstream)
- Move list_org_repository_security_advisories from orgs -> security_advisories
- Remove check_dependency_vulnerabilities from security_advisories (gone upstream)
- Remove run_secret_scanning from secret_protection (not in server default listing)
- Add create_pull_request_with_copilot to copilot (remote)
- Register get_label in issues (dual-registered with labels, matching source)
Update TestToolsetPermissionsMapping expected toolsets accordingly.
Co-Authored-By: Claude Opus 4.8 (1M context) <noreply@anthropic.com>