Upgrade to Vaadin 24.8.6

See gh-1878

Signed-off-by: Zhe Sun <[email protected]>

Author: ZheSun88

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

@@ -169,7 +169,7 @@ initializr:
           - compatibilityRange: "[3.4.0,3.5.0-M1)"
             version: 24.7.11
           - compatibilityRange: "[3.5.0-M1,4.0.0-M1)"
-            version: 24.8.3
+            version: 24.8.6
     platform:
       compatibilityRange: "3.4.0"
   dependencies: