Merge pull request #54 from heroku/dependabot/pip/mcp-clientserver--1.21.0

Bump mcp[client,server] from 1.20.0 to 1.21.0

Author: jttyeung

requirements.txt

@@ -1,4 +1,4 @@
-mcp[client,server]==1.20.0
+mcp[client,server]==1.21.0
 fastapi==0.120.4
 uvicorn==0.38.0
 python-dotenv==1.2.1