Update Run samples to have compiler target to Java21

Author: maigovannon

run/helloworld-source/pom.xml

@@ -42,6 +42,7 @@ limitations under the License.
         <project.build.sourceEncoding>UTF-8</project.build.sourceEncoding>
         <project.reporting.outputEncoding>UTF-8</project.reporting.outputEncoding>
         <maven.compiler.source>21</maven.compiler.source>
+        <maven.compiler.target>21</maven.compiler.target>
         <maven.compiler.release>21</maven.compiler.release>
         <spring-boot.version>3.2.2</spring-boot.version>
     </properties>

run/helloworld/pom.xml

@@ -42,6 +42,7 @@ limitations under the License.
     <project.build.sourceEncoding>UTF-8</project.build.sourceEncoding>
     <project.reporting.outputEncoding>UTF-8</project.reporting.outputEncoding>
     <maven.compiler.source>21</maven.compiler.source>
+    <maven.compiler.target>21</maven.compiler.target>
     <maven.compiler.release>21</maven.compiler.release>
     <spring-boot.version>3.2.2</spring-boot.version>
   </properties>