[clang] [libclang/python] Renaming `get_version` into `get_clang_version` (PR #188515)

[Vlad Serebrennikov via cfe-commits]

Endilll wrote:

> I didn't do the paperwork to be a maintainer.

FYI having commit access does not imply being a maintainer. This would be you 10th merged PR, which is quite above our eligibility bar for commit access, if you were to ask for it as described [here](https://llvm.org/docs/DeveloperPolicy.html#obtaining-commit-access).

https://github.com/llvm/llvm-project/pull/188515