CI(promote-images): simplify & fix the job

[bayandin]

Problem

Currently, latest tag is added to the images in several cases:

github.ref_name == 'main' || github.ref_name == 'release' || github.ref_name == 'release-proxy'

This leads to a race; the latest tag jumps back and forth depending on the branch that has built images.

Summary of changes

• Do not push latest images to prod ECR (we don't use it)
• Use docker buildx imagetools instead of crane for tagging images
• Unify vm-compute-node-image job with others and use dockerhub as a first source for images (sync images with ECR)
• Tag images with latest only for commits in main

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]

3102 tests run: 2976 passed, 0 failed, 126 skipped (full report)

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Flaky tests (2)

Postgres 16

• test_timeline_deletion_with_files_stuck_in_upload_queue: debug

Postgres 14

• test_crafted_wal_end[last_wal_record_xlog_switch]: debug

Code coverage* (full report)

• functions: 31.3% (6414 of 20478 functions)
• lines: 48.0% (49312 of 102655 lines)

* collected from Rust tests only

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_{The comment gets automatically updated with the latest test results
bd380a1 at 2024-05-22T15:13:29.035Z :recycle:}