Flaky test: tests/sentry/api/helpers/test_group_index.py::MergeGroupsTest::test_metrics

Failing test: `tests/sentry/api/helpers/test_group_index.py::MergeGroupsTest::test_metrics` Sentry sha: ca860f9c94028d730c6c41f914221b3bb1f4059c Run: https://github.com/getsentry/sentry/actions/runs/22268328495 ``` tests/sentry/api/helpers/test_group_index.py:586: in test_metrics mock_metrics_incr.assert_any_call( /opt/hostedtoolcache/Python/3.13.1/x64/lib/python3.13/unittest/mock.py:1048: in assert_any_call raise AssertionError( E AssertionError: incr('grouping.merge_issues', sample_rate=1.0, tags={'platform': 'javascript', 'referer': 'issue stream', 'sdk': 'sentry.javascript.nextjs'}) call not found ```