Add python 3.13 support to CMakeLists.txt

[Ryp]

This matches the work done in 8878692 Python 3.8 was subsequently dropped as well here.

Related to vllm-project/vllm#13164

[mgoin]

Could you please take a look @LucasWilkinson @WoosukKwon

[NickLucche]

Is this just for dev or is this a python version bump of the whole project? If it's the latter we would need to change PYTHON_VERSION in the dockerfiles as well as the CI config files to make sure all deps are ok.

[Ryp]

Is this just for dev or is this a python version bump of the whole project? If it's the latter we would need to change PYTHON_VERSION in the dockerfiles as well as the CI config files to make sure all deps are ok.

To the best of my knowledge python3.13 is already covered by the CI: https://github.com/vllm-project/flash-attention/blob/main/.github/workflows/publish.yml#L46

[LucasWilkinson]

Could you please take a look @LucasWilkinson @WoosukKwon

LGTM, but ill let the CI experts have the final word

[Ryp]

@NickLucche I think your requested review changes is preventing this PR to be merged

[mgoin]

@WoosukKwon can you please merge? I do not have permission