[ci] Move arm build to alma10

[dpiparo]

This also removes some pressure from the nodes and the infrastructure in general, e.g. for caching images.

[github-actions]

Test Results

    18 files      18 suites   2d 19h 36m 3s ⏱️
 2 753 tests  2 753 ✅ 0 💤 0 ❌
47 864 runs  47 864 ✅ 0 💤 0 ❌

Results for commit abbb0ee.

♻️ This comment has been updated with latest results.

[guitargeek]

Good idea! But we need to figure out before merging if the test-root-hist-h2root failure was just the usual spurious failure and you were just very unlucky, or if it's a real problem on ARM with newer compilers that was fixed in later releases (I vaguely remember doing something like that...)

[dpiparo]

it looks like a real issue!

[guitargeek]

This issue should be fixed now with this backport: #21022