Add JDK 21 setup step in CI/CD pipeline for improved compatibility

Author: atick-faisal

.github/workflows/cd.yml

@@ -91,6 +91,13 @@ jobs:
           name: release-apk
           path: ./apk
 
+      - name: 🏗️ Set up JDK 21
+        uses: actions/setup-java@v5
+        with:
+          java-version: 21
+          distribution: 'temurin'
+          cache: gradle
+
       - name: 💎 Setup Ruby & Bundler
         uses: ruby/setup-ruby@v1
         with: