Add missing extension

src/aind_behavior_experiment_launcher/data_transfer/watchdog_service.py

@@ -291,7 +291,7 @@ def dump_manifest_config(self, path: Optional[os.PathLike] = None, make_dir: boo
         path = (Path(path) if path else Path(watch_config.flag_dir) / f"manifest_{manifest_config.name}.yaml").resolve()
         if "manifest" not in path.name:
             logger.warning("Prefix " "manifest_" " not found in file name. Appending it.")
-            path = path.with_name(f"manifest_{path.name}")
+            path = path.with_name(f"manifest_{path.name}.yaml")
 
         if make_dir and not path.parent.exists():
             path.parent.mkdir(parents=True, exist_ok=True)