Update hardcoded vaadin version to 24.9.7 (#4975)

* Update hardcoded vaadin version to 24.9.7

* Update _vaadin-version.adoc

---------

Co-authored-by: Zhe Sun <[email protected]>

Author: vaadin-bot

articles/_vaadin-version.adoc

@@ -1,4 +1,4 @@
-:vaadin-version: 24.9.6
-:vaadin-flow-version: 24.9.6
+:vaadin-version: 24.9.7
+:vaadin-flow-version: 24.9.7
 :vaadin-seven-version: 7.7.38
 :vaadin-eight-version: 8.20.0