[llvm] [Github] Explicitly requesting Ubuntu 22.04 for SPIRV test (PR #122395)

[Farzon Lotfi via llvm-commits]

farzonl wrote:

 > We would just get the system default installation of Python (which already exists), which precludes us from testing with different python versions.

I apologize if this is a dumb question, but If we need multiple python versions, why aren't we using pyenv to toggle between versions? 

https://github.com/llvm/llvm-project/pull/122395