add missing workflow steps

.forgejo/workflows/publish.yml

@@ -7,6 +7,11 @@ jobs:
     runs-on: docker
     steps:
     - uses: actions/checkout@v4
+    - uses: https://github.com/actions/setup-java@v4
+      with:
+        distribution: 'temurin'
+        java-version: 17
+    - uses: https://github.com/gradle/actions/setup-gradle@v3
     - name: Build
       run: |
         chmod +x ./gradlew