Grafana: fix flaky PromLink.test.tsx test

Job description

Upstream issue: https://github.com/grafana/grafana/issues/74382 Need a contributor to fix Grafana issue 74382: the PromLink.test.tsx test is flaky and needs a permanent fix. Scope: Reproduce the flaky behavior in Grafana's test suite Identify the root cause in public/app/plugins/datasource/prometheus/components/PromLink.test.tsx or closely related code Implement a stable fix Update or add tests as needed so the suite is reliable Deliverables: A GitHub PR against grafana/grafana Clear notes on the root cause of the flake Test evidence showing the targeted test is stable Link to the upstream issue and PR in your final submission Quality bar: Prefer a true root cause fix over increasing timeouts or papering over the failure Keep the patch focused and production safe Mention any tradeoffs if the repo's existing test utilities constrain the solution Submission should include: PR URL Commit hash Commands run and test output summary