fix: gcloud auth for jetbrains backend-plugin gha workflow

Author: Andrea Falzetti

.github/workflows/jetbrains-update-backend-latest.yml

@@ -34,6 +34,10 @@ jobs:
           key: ${{ runner.os }}-leeway-cache-${{ hashFiles('backend-plugin.version') }}
           restore-keys: |
             ${{ runner.os }}-leeway-cache-
+      - name: Auth Google Cloud SDK
+        uses: google-github-actions/auth@v0
+        with:
+          credentials_json: ${{ secrets.GCP_SA_KEY }}
       - name: Set up Google Cloud SDK
         uses: google-github-actions/setup-gcloud@v0
         with: