Enable Jakarta EE 11 for the Spring Boot sample application.

PiperOrigin-RevId: 853528710
Change-Id: I51f899018792f821864c3e66f4811a9cde8fd8f0

Author: ludoch

applications/springboot/src/main/webapp/WEB-INF/appengine-web.xml

@@ -19,6 +19,7 @@
   <system-properties>
     <property name="java.util.logging.config.file" value="WEB-INF/classes/logging.properties"/>
     <property name="appengine.use.jetty121" value="true"/>
+    <property name="appengine.use.EE11" value="true"/>
   </system-properties>
   <instance-class>F4</instance-class>
 </appengine-web-app>