test: add fastmcp to tox population script

Author: constantinius

scripts/populate_tox/config.py

@@ -248,6 +248,12 @@
             "*": ["pytest-asyncio"],
         },
     },
+    "fastmcp": {
+        "package": "fastmcp",
+        "deps": {
+            "*": ["pytest-asyncio"],
+        },
+    },
     "openai-base": {
         "package": "openai",
         "integration_name": "openai",