Fix flaky performance test threshold

Increase timeout threshold from 0.1s to 0.5s in test_server_performance_no_latency
to accommodate slower CI runners (Python 3.13 on ubuntu-latest). The test still
catches real performance regressions while being more forgiving on slower hardware.

Co-authored-by: Bill Easton <strawgate@users.noreply.github.com>

tests/server/providers/openapi/test_comprehensive.py

@@ -733,7 +733,7 @@ class TestOpenAPIComprehensive:
 
         # Should be very fast (no code generation)
         initialization_time = end_time - start_time
-        assert initialization_time < 0.1  # Should be under 100ms
+        assert initialization_time < 0.5  # Should be under 500ms
 
         # Verify provider was created correctly
         assert provider is not None