Try improve async tests timeout

Author: T4rk1n

dash/background_callback/managers/diskcache_manager.py

@@ -287,10 +287,14 @@ async def async_run():
                         }
                     },
                 )
+
             if asyncio.iscoroutine(user_callback_output):
                 user_callback_output = await user_callback_output
             if not errored:
-                cache.set(result_key, user_callback_output)
+                try:
+                    cache.set(result_key, user_callback_output)
+                except Exception as err:
+                    print(f"Diskcache manager couldn't save output: {err}")
 
         if asyncio.iscoroutinefunction(fn):
             func = partial(ctx.run, async_run)

tests/background_callback/utils.py

@@ -150,6 +150,8 @@ def setup_background_callback_app(manager_name, app_name):
                 for job in manager.running_jobs:
                     manager.terminate_job(job)
 
+            time.sleep(1)
+
             shutil.rmtree(cache_directory, ignore_errors=True)
             os.environ.pop("LONG_CALLBACK_MANAGER")
             os.environ.pop("DISKCACHE_DIR")