Fixing EE8 GAE 21 sample to be complied to Java21.

Author: maigovannon

appengine-java21/ee8/analytics/pom.xml

@@ -32,8 +32,8 @@
   </parent>
 
   <properties>
-    <maven.compiler.target>25</maven.compiler.target>
-    <maven.compiler.source>25</maven.compiler.source>
+    <maven.compiler.target>21</maven.compiler.target>
+    <maven.compiler.source>21</maven.compiler.source>
     <appengine.sdk.version>3.0.1</appengine.sdk.version>
   </properties>