v1.9.0

@mopg

Protocol Version Update

Now the latest protocol version for Python SDK is 2025-03-26

Fix typo in authentication section of README by @mopg in #676
fix: 204 is an acceptable response to DELETEing the session by @nbarbettini in #697
Minor tweaks to README for Streamable HTTP by @evalstate in #690
Properly infer prefix for SSE messages by @jlowin in #659
Simple Auth Example to use shttp in addition to sse by @ihrpr in #695
Create ClientSessionGroup for managing multiple session connections. by @mkeid in #639
fix typo: server has get_context attribute instead of request_context. by @shimizukawa in #446
docs: clarify LLM API configuration in mcp_simple_chatbot README by @ddltn in #487
fix: Add checks and better error messages on server object for mcp run by @john0312 in #297
Fix hanging on streams when stdio_client exiting by @LionNatsu in #559
feat: add message to ProgressNotification by @aksheyd in #435
Update CI configuration to support multiple OS environments by @DanielAvdar in #708
feat: add cursor pagination support to all client list methods by @jerome3o-anthropic in #718
Add example for stateless server with JSON response by @5enxia in #704
Include server examples folder in pyright check by @ihrpr in #667
Set 2025-03-26 as the latest protocol version by @ihrpr in #719
Fix example for multiple stateless servers by @ihrpr in #720
fix: Update @mcp.resource to use function documentation as default descrip… by @jingyugao in #489
Add progress notification callback for client by @ihrpr in #721
Servers to accept older versions of client by @ihrpr in #722

Full Changelog: v1.8.1...v1.9.0