[llvm] [lit] Remove legacy python version checks (NFC) (PR #105948)

[Aiden Grossman via llvm-commits]

boomanaiden154 wrote:

> this one was just spotted in https://github.com/llvm/llvm-project/pull/105759, I updated this PR to include all of them i found in lit

Thanks! The rest can probably be cleaned up separately when someone gets to them and can ping maintainers.

https://github.com/llvm/llvm-project/pull/105948