Wait longer to avoid flakiness (#6001)

Quick fix for a flaky test introduced in #5950.

extensions/positron-python/python_files/positron/positron_ipykernel/tests/test_positron_jedilsp.py

@@ -4,7 +4,7 @@
 #
 
 import os
-import time
+from threading import Timer
 from typing import Any, Dict, List, Optional, cast
 from unittest.mock import Mock
 
@@ -332,5 +332,7 @@ def test_close_notebook_cell_clears_diagnostics():
 
     # Wait for the diagnostics to be published
     server.publish_diagnostics.assert_not_called()
-    time.sleep(0.06)
+    timers: List[Timer] = list(_clear_diagnostics_debounced.timers.values())  # type: ignore
+    for timer in timers:
+        timer.join()
     server.publish_diagnostics.assert_called_once_with(params.text_document.uri, [])

extensions/positron-python/python_files/positron/positron_ipykernel/utils.py

@@ -497,6 +497,9 @@ def run() -> None:
         # Store the interval on the debounced function; we lower the interval for faster tests.
         debounced.interval_s = interval_s  # type: ignore
 
+        # Store timers on the debounced function; we wait for them to finish in tests.
+        debounced.timers = timers  # type: ignore
+
         return debounced
 
     return wrapper