[libclang/python] type-ignore Any returns from library calls (#101310)

On its own, this change leads to _more_ strict typing errors as the
functions are mostly not annotated so far, so the `# type: ignore`s are
reported as Unused. This is part of the work leading up to #78114
though, and one of the bigger parts factored out from it, so these will
later lead to less strict typing errors as the functions are annotated
with return types.

Author: DeinAlptraum