Add test job, update build job

.forgejo/workflows/build-and-test.yml

@@ -13,7 +13,7 @@ jobs:
    - name: Checkout
      uses: https://code.forgejo.org/actions/checkout@v4
    - name: Compile
-     run: ./gradlew --no-daemon build
+     run: ./gradlew --no-daemon jar javadocJar sourceJar
    - name: Upload library JARs
      uses: https://code.forgejo.org/forgejo/upload-artifact@v4
      with:
@@ -37,3 +37,12 @@ jobs:
       path: |
         **/build/libs/*-source.jar
       if-no-files-found: error
+ test:
+  runs-on: docker
+  container:
+   image: git.staropensource.de/staropensource/actions-docker:java
+  steps:
+   - name: Checkout
+     uses: https://code.forgejo.org/actions/checkout@v4
+   - name: Run tests
+     run: ./gradlew --no-daemon test