Fix deadlock when restarting scripts (#49410)

homeassistant/helpers/script.py

@@ -1203,12 +1203,9 @@ class Script:
             self._changed()
             raise
 
-    async def _async_stop(self, update_state, spare=None):
-        aws = [
-            asyncio.create_task(run.async_stop()) for run in self._runs if run != spare
-        ]
-        if not aws:
-            return
+    async def _async_stop(
+        self, aws: list[asyncio.Task], update_state: bool, spare: _ScriptRun | None
+    ) -> None:
         await asyncio.wait(aws)
         if update_state:
             self._changed()
@@ -1217,7 +1214,15 @@ class Script:
         self, update_state: bool = True, spare: _ScriptRun | None = None
     ) -> None:
         """Stop running script."""
-        await asyncio.shield(self._async_stop(update_state, spare))
+        # Collect a a list of script runs to stop. This must be done before calling
+        # asyncio.shield as asyncio.shield yields to the event loop, which would cause
+        # us to wait for script runs added after the call to async_stop.
+        aws = [
+            asyncio.create_task(run.async_stop()) for run in self._runs if run != spare
+        ]
+        if not aws:
+            return
+        await asyncio.shield(self._async_stop(aws, update_state, spare))
 
     async def _async_get_condition(self, config):
         if isinstance(config, template.Template):