Update msmart-ng to 2026.4.0 (#409)

Author: mill1000

custom_components/midea_ac/manifest.json

@@ -13,7 +13,7 @@
     "msmart"
   ],
   "requirements": [
-    "msmart-ng==2026.3.0"
+    "msmart-ng==2026.4.0"
   ],
   "version": "2026.2.0"
 }