[clang] [libclang/python] Clean up tests (PR #114383)

[Vlad Serebrennikov via cfe-commits]

https://github.com/Endilll requested changes to this pull request.

Thank you for putting effort into this!
You're mixing up non-functional and functional changes here (thank you for highlighting the mistake you've previously made, it's buried rather deep!), so I'd like to ask you to split this up into more focused PRs. The ones I see: fixing the test, paths, imports, unused variables.

https://github.com/llvm/llvm-project/pull/114383