chore: swing kit 2.4.0 (24.8) (#7676)

Author: ZheSun88

versions.json

@@ -423,7 +423,7 @@
             "jsVersion": "3.1.1"
         },
         "swing-kit": {
-            "javaVersion": "2.3.0"
+            "javaVersion": "2.4.0"
         },
         "vaadin-collaboration-engine": {
             "javaVersion": "6.4.0"