[CI/CD] Added java setup action in testing workflow

Author: kchousos

.github/workflows/tests.yml

@@ -17,6 +17,11 @@ jobs:
     steps:
     - uses: actions/checkout@v4
 
+    - uses: actions/setup-java@v5
+      with:
+        distribution: 'temurin'
+        java-version: '21'
+
     - name: Install uv
       uses: astral-sh/setup-uv@v5
       with: