Heal 3.11 coverage tracing at JSONRPCDispatcher.run() exit

run() ends via its own internal cancelled task-group join; on 3.11 a
direct `await dispatcher.run(...)` (not via tg.start) loses tracing
on the lines that follow. Heal at the exit, matching the pattern in
ClientSession.__aexit__.

Author: maxisbey

src/mcp/shared/jsonrpc_dispatcher.py

@@ -22,6 +22,7 @@
 from pydantic import ValidationError
 from typing_extensions import TypeVar
 
+from mcp.shared._compat import resync_tracer
 from mcp.shared._otel import inject_trace_context, otel_span
 from mcp.shared._stream_protocols import ReadStream, WriteStream
 from mcp.shared.dispatcher import CallOptions, DispatchContext, Dispatcher, OnNotify, OnRequest, ProgressFnT
@@ -447,6 +448,7 @@ async def run(
             self._closed = True
             self._tg = None
             self._fan_out_closed()
+            await resync_tracer()
 
     async def _dispatch(
         self,