[clang] [libclang/python] Fix evaluation of the unsigned enumeration values, #108766 (PR #108769)

[Jannick Kremer via cfe-commits]

DeinAlptraum wrote:

@fursov yes, since you are a new contributor, you cannot merge this yourself. I can, but I am also still relatively new so I would like someone else to confirm that this change is good to go - so we're just waiting for him to take a look as well :)

https://github.com/llvm/llvm-project/pull/108769