fix: Update MCP Publisher version in workflow

- 🔧 Changed MCP Publisher download link to specific version v1.2.3
- 📦 Ensures consistent installation of the MCP Publisher for builds

Author: jamesmontemagno

.github/workflows/publish-mcp-registry.yml

@@ -40,7 +40,7 @@ jobs:
 
       - name: Install MCP Publisher
         run: |
-          curl -L "https://github.com/modelcontextprotocol/registry/releases/download/latest/mcp-publisher_$(uname -s | tr '[:upper:]' '[:lower:]')_$(uname -m | sed 's/x86_64/amd64/;s/aarch64/arm64/').tar.gz" | tar xz mcp-publisher
+          curl -L "https://github.com/modelcontextprotocol/registry/releases/download/v1.2.3/mcp-publisher_$(uname -s | tr '[:upper:]' '[:lower:]')_$(uname -m | sed 's/x86_64/amd64/;s/aarch64/arm64/').tar.gz" | tar xz mcp-publisher
 
       - name: Login to MCP Registry
         run: ./mcp-publisher login github-oidc