Remove Tasks (SEP-1686) from the SDK (#2714)

Author: maxisbey

README.v2.md

@@ -2489,7 +2489,6 @@ MCP servers declare capabilities during initialization:
 ## Documentation
 
 - [API Reference](https://modelcontextprotocol.github.io/python-sdk/api/)
-- [Experimental Features (Tasks)](https://modelcontextprotocol.github.io/python-sdk/experimental/tasks/)
 - [Model Context Protocol documentation](https://modelcontextprotocol.io)
 - [Model Context Protocol specification](https://modelcontextprotocol.io/specification/latest)
 - [Officially supported servers](https://github.com/modelcontextprotocol/servers)