test: fix flaky stats logging interval timing test (#1463)

Replace real time.sleep() calls with mocked time.time() to eliminate
timing dependencies that caused intermittent CI failures. The test
would occasionally fail when execution overhead pushed total elapsed
time over the 1.0 second threshold, triggering unexpected stats logging.

Mocking time.time() ensures deterministic behavior across all
environments
and reduces test execution time from ~1.16s to ~0.02s.

Author: Pouyanpi

tests/test_cache_lfu.py

@@ -553,21 +553,24 @@ def test_stats_logging_interval_timing(self):
 
         with patch.object(
             logging.getLogger("nemoguardrails.llm.cache.lfu"), "info"
-        ) as mock_log:
-            # Multiple operations within interval
+        ) as mock_log, patch("time.time") as mock_time:
+            current_time = [0.0]
+
+            def time_side_effect():
+                return current_time[0]
+
+            mock_time.side_effect = time_side_effect
+
             for i in range(10):
                 cache.put(f"key{i}", f"value{i}")
                 cache.get(f"key{i}")
-                time.sleep(0.05)  # Total time < 1.0
+                current_time[0] += 0.05
 
-            # Should not have logged yet
             self.assertEqual(mock_log.call_count, 0)
 
-            # Wait for interval to pass
-            time.sleep(0.6)
-            cache.get("key1")  # Trigger check
+            current_time[0] += 0.6
+            cache.get("key1")
 
-            # Now should have logged once
             self.assertEqual(mock_log.call_count, 1)
 
     def test_stats_logging_with_updates(self):