Make test extensions upgrade work with absent images

[a-masterov]

Problem

CI does not pass for the compute release due to the absence of some images

Summary of changes

Now we use the images from the old non-compute releases for non-compute images

[jcgruenhage]

lgtm

[jcgruenhage]

Looks good to me! Thanks for the quick turnaround :)

[github-actions]

7744 tests run: 7366 passed, 0 failed, 378 skipped (full report)

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Flaky tests (1)

Postgres 17

• test_pageserver_chaos[4]: release-arm64-with-lfc

Code coverage* (full report)

• functions: 32.8% (8640 of 26363 functions)
• lines: 48.6% (73202 of 150508 lines)

* collected from Rust tests only

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_{The comment gets automatically updated with the latest test results
04a33e8 at 2025-02-28T11:14:44.699Z :recycle:}