fix MCP publisher installation: use binary download instead of non-existent npm package

.github/workflows/publish-mcp.yml

···
 
       - name: install mcp publisher
         run: |
-          npm install -g @modelcontextprotocol/publisher
+          curl -L "https://github.com/modelcontextprotocol/registry/releases/download/latest/mcp-publisher_linux_amd64.tar.gz" | tar xz
+          sudo mv mcp-publisher /usr/local/bin/
 
       - name: login to mcp registry (github oidc)
         run: mcp-publisher login github-oidc