*IT tests in x-pack/plugin/core silently ignored?

[ywelsch]

*IT tests in x-pack/plugin/coreseems to be silently ignored. I was working on a patch for source only snapshots and noticed that SourceOnlySnapshotIT is failing on master (without my changes), but this is not being picked up by CI. Same probably applies to ReloadSynonymAnalyzerIT and other *IT tests?

This looks potentially dangerous as test coverage is not what we would expect it to be.

[elasticmachine]

Pinging @elastic/es-core-infra (:Core/Infra/Build)

[rjernst]

I've found the problem, and it is very unfortunate. It appears all IT tests in xpack have been disabled for over a year. The IT tests in xpack are run under a separate test runner task called internalClusterTest. In moving where this task is created, it was accidentally not added to the check task, so CI has not known to run it.

I'll open a PR to re-enable, and mute any failing tests with test-failure issues as we would any other failing test.

[rjernst]

After going through all the xpack modules defining internalClusterTask, only the core tests were left out of check. This should be fixed by #53444.