build_manager: stop underlying task runner instances on a module-level stop call

build_manager/cleaner.py

@@ -48,6 +48,13 @@ class BuildArtifactsCleaner:
         self.logger.info("Starting BuildArtifactsCleaner")
         self.__runner.start()
 
+    def stop(self) -> None:
+        """
+        Stop BuildArtifactsCleaner.
+        """
+        self.logger.info("Stopping BuildArtifactsCleaner")
+        self.__runner.stop()
+
     def __stale_artifacts_path_list(self) -> list:
         """
         Returns a list of paths to stale build artifacts.

build_manager/progress_updater.py

@@ -53,6 +53,13 @@ class BuildProgressUpdater:
         self.logger.info("Starting BuildProgressUpdater.")
         self.__runner.start()
 
+    def stop(self) -> None:
+        """
+        Stop BuildProgressUpdater.
+        """
+        self.logger.info("Stopping BuildProgressUpdater.")
+        self.__runner.stop()
+
     def __calc_running_build_progress_percent(self, build_id: str) -> int:
         """
         Calculate the progress percentage of a running build.