Update vaadin version to 24.5.0.alpha9 (vaadin#3596)

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

Author: vaadin-bot

pom.xml

@@ -13,7 +13,7 @@
         <project.reporting.outputEncoding>UTF-8</project.reporting.outputEncoding>
 
         <!-- tag::vaadin-version[] -->
-        <vaadin.version>24.5.0.alpha8</vaadin.version>
+        <vaadin.version>24.5.0.alpha9</vaadin.version>
         <!-- end::vaadin-version[] -->
 
         <drivers.dir>${project.basedir}/drivers</drivers.dir>