[grpc-io] gRPC-Python Change of support for MacOS<10.10

[Xuan Wang]

Hi All,

If you're using MacOS with version higher than 10.10, you won't be impacted by this change.

gPRC Python team is working on deprecate pkg_resources module. As part of the effort, we'll stop overriding MACOSX_DEPLOYMENT_TARGET, this might cause some compatibility issues for MacOS with versions lower than 10.10.

Please let us know if you have any questions or concerns.

Related PR: https://github.com/grpc/grpc/pull/35849

Thanks,

Xuan