fix(say-server): pin mcp to released version instead of main branch (#366)

The main branch of the MCP Python SDK has removed `FastMCP` (likely
moving it to the standalone `fastmcp` package), causing import errors.
Pin to mcp>=1.26.0 which is the latest release that still includes
`mcp.server.fastmcp`.

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Co-authored-by: Claude Opus 4.5 <noreply@anthropic.com>

Author: ochafik

examples/say-server/server.py

@@ -2,7 +2,7 @@
 # /// script
 # requires-python = ">=3.10"
 # dependencies = [
-#     "mcp @ git+https://github.com/modelcontextprotocol/python-sdk@main",
+#     "mcp>=1.26.0",
 #     "uvicorn>=0.34.0",
 #     "starlette>=0.46.0",
 #     "pocket-tts>=1.0.1",