Update GHA JDK to the latest LTS version (21)

Author: SimonMarquis

.github/workflows/build_and_test.yml

@@ -25,10 +25,10 @@ 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'
 
       - name: Setup Gradle
@@ -112,10 +112,10 @@ jobs:
       - name: Copy CI gradle.properties
         run: mkdir -p ~/.gradle ; cp .github/ci-gradle.properties ~/.gradle/gradle.properties
 
-      - name: Set up JDK 17
+      - name: Set up JDK 21
         uses: actions/setup-java@v4
         with:
-          java-version: '17'
+          java-version: '21'
           distribution: 'temurin'
 
       - name: Setup Gradle
@@ -143,4 +143,4 @@ jobs:
         uses: actions/upload-artifact@v4
         with:
           name: test-reports-${{ matrix.api-level }}
-          path: '**/build/reports/androidTests'
+          path: '**/build/reports/androidTests'