ci: use reusable workflow for MacOs build

[fedordikarev]

Closes: https://github.com/neondatabase/cloud/issues/17784

Problem

Currently, we run the whole CI pipeline for any changes. It's slow and expensive.

Suggestion

Starting with MacOs builds:

• check what files were changed
• rebuild only needed parts
• reuse results from previous builds when available
• run builds in parallel when possible

[github-actions]

7227 tests run: 6875 passed, 0 failed, 352 skipped (full report)

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Flaky tests (2)

Postgres 16

• test_create_churn_during_restart: release-arm64

Postgres 15

• test_physical_replication_config_mismatch_max_locks_per_transaction: release-arm64

Code coverage* (full report)

• functions: 31.2% (8413 of 26961 functions)
• lines: 48.0% (66801 of 139225 lines)

* collected from Rust tests only

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_{The comment gets automatically updated with the latest test results
73d1824 at 2025-01-07T18:57:08.104Z :recycle:}

[bayandin]

Currently, we run the whole CI pipeline for any changes. It's slow and expensive.

I wonder what the numbers are? For cases with full cache and no cache

[bayandin]

Awesome!