Update MacOS deployment target to 11.0 (#99857)
MacOS-10.9 (Mavericks) was released a decade ago, update it to Big Sur, that was released in 2020. But keep platform name to 10_9, as `pip` treats platform as one CPython was built on, not the one it runs on. Delete duplicate `compile_x86_64` function from `macos_build.sh` and specify platform name there.
Should fix MacOS x86 periodic build failures.
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### <samp>🤖 Generated by Copilot at ee4d5a8</samp>
> _`macosx_10_9` wheel_
> _Aligns with PyTorch support_
> _Winter of updates_
Pull Request resolved: https://github.com/pytorch/pytorch/pull/99857
Approved by: https://github.com/huydhn, https://github.com/atalman
