Change macos runners to macos-12. (requires updating xcode to 13.1)

[jonsimantov]

Description

Provide details of the change, and generalize the change in the PR title above.

Update macos runners to use macos-12 (public beta) instead of macos-latest (equivalent to macos-11).

This change requires updating to Xcode 13.1 as a stopgap solution; we will update to Xcode 13.2.1 or Xcode 13.3.1 in a subsequently-merged PR. Updating to Xcode 13 necessitates updating iOS simulator versions as well.

Note: skipping release notes check, because the subsequent PR (#915) updates the release notes with the new Xcode version requirement.

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Testing

Describe how you've tested these changes. Link any manually triggered Integration tests or CPP binary SDK Packaging Github Action workflows, if applicable.

Integration test run in the PR.
C++ packaging step here: https://github.com/firebase/firebase-cpp-sdk/actions/runs/2260453371

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Type of Change

Place an x the applicable box:

• Bug fix. Add the issue # below if applicable.
• New feature. A non-breaking change which adds functionality.
• Other, such as a build process or documentation change.

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Notes

• Bug fixes and feature changes require an update to the Release Notes section of release_build_files/readme.md.
• Read the contribution guidelines CONTRIBUTING.md.
• Changes to the public API require an internal API review. If you'd like to help us make Firebase APIs better, please propose your change in a feature request so that we can discuss it together.

[github-actions]

✅  Integration test succeeded!

Requested by @jonsimantov on commit 25da83c
Last updated: Tue May 3 13:28 PDT 2022
View integration test log & download artifacts

[dconeybe]

FYI The Xcode upgrade could experience build errors if compiling against the iOS SDK that does not have an Xcode 13.3.1 fix (firebase/firebase-ios-sdk#9705).

[jonsimantov]

FYI The Xcode upgrade could experience build errors if compiling against the iOS SDK that does not have an Xcode 13.3.1 fix (firebase/firebase-ios-sdk#9705).

Thanks. I'll be trying this in the 9.0.0 branch as well.

[sunmou99]

Updated the macos runner name with a matrix variable.
Testing workflow: https://github.com/firebase/firebase-cpp-sdk/actions/runs/2260685352

[jonsimantov]

Updated the macos runner name with a matrix variable. Testing workflow: https://github.com/firebase/firebase-cpp-sdk/actions/runs/2260685352

Nice, thanks! I just kicked off a new tests-requested on this PR so you can cancel your separate test run if you want.