Workaround for strange type hint problem

[mrbean-bremen]

• fixes 'Path | str' like type hints in wrapped functions inside an fs dependent fixture
• see New-style `Path | str` union doesn't seem to work in fixture #1242

Tasks

• Unit tests added that reproduce the issue or prove feature is working
• Fix or feature added
• Entry to release notes added
• Pre-commit CI shows no errors
• Unit tests passing