chore: update Prefect MCP status in docs (#19213)

Author: zzstoatzz

docs/v3/how-to-guides/ai/use-prefect-mcp-server.mdx

@@ -7,7 +7,7 @@ description: Connect AI assistants to Prefect using the Model Context Protocol.
 The Prefect MCP server enables AI assistants to interact with your Prefect workflows and infrastructure through the [Model Context Protocol (MCP)](https://modelcontextprotocol.io/). This integration allows AI tools like Claude Code, Cursor, and Codex CLI to help you monitor deployments, debug flow runs, query infrastructure, and more.
 
 <Warning>
-The Prefect MCP server is currently in alpha. APIs, features, and behaviors may change without notice. We encourage you to try it out and provide feedback through [GitHub issues](https://github.com/PrefectHQ/prefect-mcp-server/issues).
+The Prefect MCP server is currently in beta. APIs, features, and behaviors may change without notice. We encourage you to try it out and provide feedback through [GitHub issues](https://github.com/PrefectHQ/prefect-mcp-server/issues).
 </Warning>
 
 ## What is the Prefect MCP server?