fix forgejo deploy workflow

.forgejo/workflows/deploy-prod.yml

@@ -14,9 +14,10 @@ jobs:
         env:
           DEPLOY_SSH_KEY: ${{ secrets.DEPLOY_SSH_KEY }}
         run: |
-          rm -rf /var/lib/apt/lists/*
+          if ! command -v ssh >/dev/null 2>&1; then
             apt-get update
             apt-get install -y --no-install-recommends openssh-client
+          fi
 
           mkdir -p ~/.ssh
           printf '%s\n' "$DEPLOY_SSH_KEY" > ~/.ssh/id_ed25519