fix(ci): make publish-website SSH steps continue-on-error

The deploy steps in build-linux and deploy-playstore already use
continue-on-error: true when SSH secrets may be absent, but
publish-website did not — causing a hard failure when SSH_USER is unset.

Co-Authored-By: Claude Sonnet 4.6 <noreply@anthropic.com>

.forgejo/workflows/ci.yml

@@ -147,6 +147,7 @@ jobs:
           echo "experimental-features = nix-command flakes" >> ~/.config/nix/nix.conf
 
       - name: Set up SSH key
+        continue-on-error: true
         env:
           SSH_PRIVATE_KEY: ${{ secrets.SSH_PRIVATE_KEY }}
         run: |
@@ -155,6 +156,7 @@ jobs:
           chmod 600 ~/.ssh/id_rsa
 
       - name: Generate build history and deploy website
+        continue-on-error: true
         env:
           SSH_USER: ${{ secrets.SSH_USER }}
           SSH_HOST: ${{ secrets.SSH_HOST }}