Force full rebuild in CI with --no-cache

Podman was reusing the RUN npm run build layer from before the
vite.define token injection was added, causing webmentions to be
built without the token.

Co-Authored-By: Claude Opus 4.7 <noreply@anthropic.com>

.forgejo/workflows/deploy.yml

@@ -35,6 +35,7 @@ jobs:
         run: |
           cd "${DEPLOY_DIR}"
           sudo podman build \
+            --no-cache \
             --build-arg WEBMENTION_TOKEN="${{ secrets.WEBMENTION_TOKEN }}" \
             -t localhost/adrian-altner.de:latest .