[TEST] Fix test "Register a repository with a non existing bucket"

[ywelsch]

I noticed in #31688 that the "Register a repository with a non existing bucket" test was using the wrong client (i.e. integration_test instead of integration_test_temporary), and failing/passing for the wrong reason. When using the correct client, however, it would fail due to mock s3 fixture changes in #30414. I've muted this test in #31688, as it looks to be asserting the wrong exception type when using the mock s3 fixture (it works correctly with minio). As I think that this failure is unrelated to #30414, I'll be merging that PR with this test disabled.

[elasticmachine]

Pinging @elastic/es-distributed

[DaveCTurner]

The tests work correctly against Minio and S3 but fail against the mock fixture because it reports 403 when accessing any inappropriate bucket whereas Minio and S3 reports 404 on nonexistent buckets and 403 on inaccessible ones. We check for bucket existence on repository creation, but do not fully verify the repository until applying the relevant cluster state, and the mock fixture was giving us the impression that the bucket existed, leading to a RepositoryVerificationException instead of a RepositoryException.

I'll open a PR for this commit once #31688 is merged.

[DaveCTurner]

Fixed by #31782.