Set MQTT quality scale to platinum (#135612)

* Set MQTT quality scale to platinum

* Add  test for type stub

homeassistant/components/mqtt/manifest.json

@@ -7,7 +7,7 @@
   "dependencies": ["file_upload", "http"],
   "documentation": "https://www.home-assistant.io/integrations/mqtt",
   "iot_class": "local_push",
-  "quality_scale": "gold",
+  "quality_scale": "platinum",
   "requirements": ["paho-mqtt==1.6.1"],
   "single_config_entry": true
 }

homeassistant/components/mqtt/quality_scale.yaml

@@ -123,6 +123,7 @@ rules:
     comment: |
       This integration does not use web sessions.
   strict-typing:
-    status: todo
-    comment: |
-      Requirement 'paho-mqtt==1.6.1' appears untyped
+    status: done
+    comment: >
+      Typing for 'paho-mqtt==1.6.1' supported via 'types-paho-mqtt==1.6.0.20240321'
+      (requirements_test.txt).

script/hassfest/quality_scale_validation/strict_typing.py

@@ -43,6 +43,10 @@ def _check_requirements_are_typed(integration: Integration) -> list[str]:
 
         if not any(file for file in distribution.files if file.name == "py.typed"):
             # no py.typed file
+            try:
+                metadata.distribution(f"types-{requirement_name}")
+            except metadata.PackageNotFoundError:
+                # also no stubs-only package
                 invalid_requirements.append(requirement)
 
     return invalid_requirements