fix deadlock on tests

src/textual/_animator.py

@@ -188,10 +188,13 @@ class Animator:
 
     async def stop(self) -> None:
         """Stop the animator task."""
+        try:
             try:
                 await self._timer.stop()
             except asyncio.CancelledError:
                 pass
+        finally:
+            self._idle_event.set()
 
     def bind(self, obj: object) -> BoundAnimator:
         """Bind the animator to a given objects."""

src/textual/app.py

@@ -803,8 +803,10 @@ class App(Generic[ReturnType], DOMNode):
                 terminal_size=size,
             )
         finally:
+            try:
                 if auto_pilot_task is not None:
                     await auto_pilot_task
+            finally:
                 await app._shutdown()
 
         return app.return_value
@@ -1291,6 +1293,10 @@ class App(Generic[ReturnType], DOMNode):
 
                 await self.animator.start()
 
+            except Exception:
+                await self.animator.stop()
+                raise
+
             finally:
                 await self._ready()
                 await invoke_ready_callback()
@@ -1303,11 +1309,12 @@ class App(Generic[ReturnType], DOMNode):
                 pass
             finally:
                 self._running = False
+                try:
+                    await self.animator.stop()
+                finally:
                     for timer in list(self._timers):
                         await timer.stop()
 
-            await self.animator.stop()
-
         self._running = True
         try:
             load_event = events.Load(sender=self)