I'm in the processing of updating both MacOS and Xcode versions across our CI fleet, which already led to some build failures like https://buildkite.com/bazel/google-bazel-presubmit/builds/63039#018608b6-324b-4d4b-9e0a-ac8b8a77b8bc.

I'm working on a fix.