Flaky test: tests/snuba/tasks/test_unmerge.py::UnmergeTestCase::test_unmerge

Failing test: `tests/snuba/tasks/test_unmerge.py::UnmergeTestCase::test_unmerge` Sentry sha: 405c781e4bcb9380607169cc7de045bcc30823e6 Run: https://github.com/getsentry/sentry/actions/runs/22270628212 ``` tests/snuba/tasks/test_unmerge.py:301: in test_unmerge assert list( E assert [(7, datetime...imezone.utc))] == [(6, datetime...imezone.utc))] E  E At index 0 diff: (7, datetime.datetime(2026, 2, 22, 4, 47, 37, tzinfo=datetime.timezone.utc), datetime.datetime(2026, 2, 22, 4, 47, 43, tzinfo=datetime.timezone.utc)) != (6, datetime.datetime(2026, 2, 22, 4, 47, 37, tzinfo=datetime.timezone.utc), datetime.datetime(2026, 2, 22, 4, 47, 42, tzinfo=datetime.timezone.utc)) E  E Full diff: E [ E ( E - 6, E ? ^ E + 7, E ? ^ E datetime.datetime(2026, 2, 22, 4, 47, 37, tzinfo=datetime.timezone.utc), E - datetime.datetime(2026, 2, 22, 4, 47, 42, tzinfo=datetime.timezone.utc), E ? ^ E + datetime.datetime(2026, 2, 22, 4, 47, 43, tzinfo=datetime.timezone.utc), E ? ^ E ), E ] ```