Place hot reload artifacts in a temp directory (#40171)

packages/flutter_tools/lib/src/run_cold.dart

diff --git a/packages/flutter_tools/lib/src/run_cold.dart b/packages/flutter_tools/lib/src/run_cold.dart
index b621c78..ddfde2e 100644
--- a/packages/flutter_tools/lib/src/run_cold.dart
+++ b/packages/flutter_tools/lib/src/run_cold.dart
@@ -206,5 +206,6 @@
       if (device.vmServices == null || device.vmServices.isEmpty)
         await device.device.stopApp(device.package);
     }
+    await super.preExit();
   }
 }