CI: make miopen-dbsync on gfx90a blocking #9877

Summary

Remove the gfx90a expect_failure for miopen-dbsync in build_tools/github_actions/fetch_test_configurations.py once gfx90a has run on rocm-libraries PRs long enough to trust it, so a gfx90a failure blocks merge like gfx942 and gfx950.

Blocked by

• CI: build gfx90a on all rocm-libraries PRs to run miopen-dbsync on gfx90a #9876: build gfx90a on all rocm-libraries PRs (live)
• History: enough consecutive green gfx90a dbsync jobs on PRs, with no unrelated flakiness. Suggested bar, to tune: at least 7 days and 30 PR jobs, plus green TheRock daily gfx90a runs. Check logs and steps, not just job conclusions (an xfail job can hide failures).

Change

Remove the gfx90a expect_failure declaration and update the tests that assert it is advisory (as in #9768). Then bump the TheRock pin in rocm-libraries so it takes effect.

Done when

After the pin bump a gfx90a dbsync failure turns the Multi-Arch CI Summary red on rocm-libraries PRs.

Related: #9875, ALMIOPEN-3246, epic ALMIOPEN-785.