Update Shelly's quality scale to platinum 🏆️ (home-assistant#156982)

Author: davidrapan

homeassistant/components/shelly/manifest.json

@@ -16,7 +16,7 @@
   "integration_type": "device",
   "iot_class": "local_push",
   "loggers": ["aioshelly"],
-  "quality_scale": "silver",
+  "quality_scale": "platinum",
   "requirements": ["aioshelly==13.19.0"],
   "zeroconf": [
     {