Setup SSH in workflow using secret

.gitea/workflows/build-deploy.yml

@@ -37,6 +37,13 @@ jobs:
         working-directory: os-league-tools-master
         run: tar -czf build.tar.gz build/
 
+      - name: Setup SSH
+        run: |
+          mkdir -p ~/.ssh
+          echo "${{ secrets.DEPLOY_SSH_KEY }}" > ~/.ssh/id_ed25519
+          chmod 600 ~/.ssh/id_ed25519
+          ssh-keyscan -H ${{ env.FRONTEND_HOST }} >> ~/.ssh/known_hosts
+
       - name: Deploy to frontend server
         run: |
           ssh sonder@${{ env.FRONTEND_HOST }} "sudo systemctl stop os-league-tools || true"