Pull #16981: Migrate to Java 21 - infra

Author: Vincent Potucek

.github/workflows/maven.yml

@@ -33,7 +33,7 @@ jobs:
       - name: Set up JDK
         uses: actions/setup-java@v4
         with:
-          java-version: 17
+          java-version: 21
           distribution: 'temurin'
 
       - name: Checkout maven

pom.xml

@@ -128,7 +128,7 @@ under the License.
   </distributionManagement>
 
   <properties>
-    <javaVersion>17</javaVersion>
+    <javaVersion>21</javaVersion>
     <maven.compiler.source>${javaVersion}</maven.compiler.source>
     <maven.compiler.target>${javaVersion}</maven.compiler.target>
     <maven.compiler.release>${javaVersion}</maven.compiler.release>