CI: build multi-arch images

[bayandin]

Problem

We don't build our docker images for ARM arch, and that makes it harder to run images on ARM (on MacBooks with Apple Silicon, for example).

Summary of changes

• Build neondatabase/neon for ARM and create a multi-arch image
• Build neondatabase/compute-node-vXX for ARM and create a multi-arch image
• Run test-images job on ARM as well

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]

3078 tests run: 2951 passed, 0 failed, 127 skipped (full report)

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Flaky tests (1)

Postgres 16

• test_timeline_deletion_with_files_stuck_in_upload_queue: debug

Code coverage* (full report)

• functions: 31.4% (6412 of 20427 functions)
• lines: 48.1% (49276 of 102532 lines)

* collected from Rust tests only

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_{The comment gets automatically updated with the latest test results
de6bbe3 at 2024-05-21T12:39:27.659Z :recycle:}

[bayandin]

Last week:

• it was implemented, but arm runners aren't reliable yet

This week:

• Check if we have enough large-arm64 runners
• Get PR merged