Polish "Upgrade to Vaadin 24.8.0"

See gh-1842

Author: snicoll

start-site/src/main/resources/application.yml

@@ -174,7 +174,7 @@ initializr:
         mappings:
           - compatibilityRange: "[3.4.0,3.5.0-M1)"
             version: 24.7.6
-          - compatibilityRange: "[3.5.0,3.6.0-M1)"
+          - compatibilityRange: "[3.5.0-M1,3.6.0-M1)"
             version: 24.8.0
     platform:
       compatibilityRange: "3.3.0"