CI: move build on macOS to a separate workflow

[bayandin]

Problem

Summary of changes

Checklist before requesting a review

• I have performed a self-review of my code.
• If it is a core feature, I have added thorough tests.
• Do we need to implement analytics? if so did you add the relevant metrics to the dashboard?
• If this PR requires public announcement, mark it with /release-notes label and add several sentences in this section.

Checklist before merging

• Do not forget to reformat commit message to not include the above checklist

[github-actions]

3042 tests run: 2927 passed, 0 failed, 115 skipped (full report)

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Flaky tests (1)

Postgres 15

• test_backward_compatibility: release

Code coverage* (full report)

• functions: 32.6% (6933 of 21275 functions)
• lines: 50.0% (54487 of 108968 lines)

* collected from Rust tests only

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_{The comment gets automatically updated with the latest test results
bf8f571 at 2024-07-05T17:33:43.133Z :recycle:}

[bayandin]

Superseded by #9392