[CI][IOS] Add a arm64 ios job for Metal (#46646)
Summary: Pull Request resolved: https://github.com/pytorch/pytorch/pull/46646
Test Plan: Imported from OSS
Reviewed By: seemethere, linbinyu
Differential Revision: D24459597
Pulled By: xta0
fbshipit-source-id: e93a3a26897614c66768804c71658928cd26ede7
