chore: Upgrade Java version from 17 to 21

Update Java version to 21 across the project:
- pom.xml: Update java.version property to 21
- maven-test.yml: Update JDK setup to version 21
- maven-publish.yml: Update JDK setup to version 21

This ensures consistency between project configuration and CI/CD pipelines.

Author: claude

.github/workflows/maven-publish.yml

@@ -18,10 +18,10 @@ jobs:
       - name: Checkout code
         uses: actions/checkout@v4
 
-      - name: Set up JDK 17
+      - name: Set up JDK 21
         uses: actions/setup-java@v4
         with:
-          java-version: '17'
+          java-version: '21'
           distribution: 'temurin'
           cache: 'maven'
 

.github/workflows/maven-test.yml

@@ -16,10 +16,10 @@ jobs:
       - name: Checkout code
         uses: actions/checkout@v4
 
-      - name: Set up JDK 17
+      - name: Set up JDK 21
         uses: actions/setup-java@v4
         with:
-          java-version: '17'
+          java-version: '21'
           distribution: 'temurin'
           cache: 'maven'
 

pom.xml

@@ -19,7 +19,7 @@
     <description>Play with Spring Boot</description>
 
     <properties>
-        <java.version>17</java.version>
+        <java.version>21</java.version>
         <hazelcast.version>5.4.0</hazelcast.version>
     </properties>