Move ADO to Xcode 13

[HeyImChris]

Please select one of the following

• I am removing an existing difference between facebook/react-native and microsoft/react-native-macos 👍
• I am cherry-picking a change from Facebook's react-native into microsoft/react-native-macos 👍
• I am making a fix / change for the macOS implementation of react-native
• I am making a change required for Microsoft usage of react-native

Summary

Now 0.66 merged into our fork, we can make the upgrade to Xcode 13. Xcode 13 requires a Mac running macOS 11.3 or later so upgrade our OS and move Xcode with it.

[Saadnajmi]

@kelset is doing a similar change with #979
Might want to coordinate there.

[pull-bot]

	Messages
📖	📋 Missing Changelog - Can you add a Changelog? To do so, add a "## Changelog" section to your PR description. A changelog entry has the following format: [CATEGORY] [TYPE] - Message. CATEGORY may be: General macOS iOS Android JavaScript Internal (for changes that do not need to be called out in the release notes) TYPE may be: Added, for new features. Changed, for changes in existing functionality. Deprecated, for soon-to-be removed features. Removed, for now removed features. Fixed, for any bug fixes. Security, in case of vulnerabilities. MESSAGE may answer "what and why" on a feature level. Use this to briefly tell React Native users about notable changes.
📖	📋 Missing Test Plan - Can you add a Test Plan? To do so, add a "## Test Plan" section to your PR description. A Test Plan lets us know how these changes were tested.

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[HeyImChris]

@kelset is doing a similar change with #979
Might want to coordinate there.

Good point, his covers what we need plus does a bit more other clean up. I can close this one and help him get his CI passing to get that review in.