feat v1.24.2: 'no light sources' color in the lights fill group

Default opacity 0 preserves the historical no-fill behavior; assigning an
opacity tints lightless rooms distinguishably from 'all lights off'.

custom_components/houseplan/manifest.json

@@ -16,5 +16,5 @@
   "issue_tracker": "https://github.com/Matysh/houseplan-card/issues",
   "requirements": [],
   "single_config_entry": true,
-  "version": "1.24.1"
+  "version": "1.24.2"
 }