[clang] [libcxx] [lldb] [llvm] [polly] [python] remove Python 3.9 specific typing annotations (PR #156868)

[Aiden Grossman via llvm-commits]

https://github.com/boomanaiden154 requested changes to this pull request.

If you have bots for this, please address specific failures rather than grepping through the entire monorepo for these constructs. A bunch of the files you have hit here (like the ones related to CI) will never be run as part of an LLVM build and are always run with python 3.10+ and thus don't need to be fixed.

https://github.com/llvm/llvm-project/pull/156868