ci: add java setup step in docs deployment

Author: levinzonr

.github/workflows/docs.yml

@@ -17,15 +17,19 @@ jobs:
       - uses: actions/setup-python@v5
         with:
           python-version: 3.x
+      - name: Setup Java
+        uses: actions/setup-java@v1
+        with:
+          java-version: 17
       - run: echo "cache_id=$(date --utc '+%V')" >> $GITHUB_ENV
-      - run: |
-          ./gradlew dokkaHtmlMultiModule
-          mv build/dokka/htmlMultiModule docs/api
       - uses: actions/cache@v4
         with:
           key: mkdocs-material-${{ env.cache_id }}
           path: .cache
           restore-keys: |
             mkdocs-material-
+      - run: |
+          ./gradlew dokkaHtmlMultiModule
+          mv build/dokka/htmlMultiModule docs/api
       - run: pip install mkdocs-material
       - run: mkdocs gh-deploy --force