How do you handle API rate limiting in automated test suites?

Our test suite hits a third-party API (Stripe sandbox) and we occasionally get 429s in CI, causing random test failures. Approaches I've considered: - Mock Stripe entirely (loses confidence we're calling the real API correctly) - Throttle requests in tests with `time.sleep` (slow) - Use the Stripe test clock and mock server (`stripe-mock`) — haven't tried this yet - Run Stripe-dependent tests in a separate slow suite How do you handle rate limits from external APIs in your test suites, especially in CI where tests run concurrently?