coverage: remove stale pragma on send_resource_list_changed

This method was only exercised by the subprocess-based integration tests,
where coverage wasn't tracked in the child process. Now that
test_integration.py runs the server in-process via Client(mcp), the
method is covered and the pragma is invalid.

Caught by strict-no-cover (ubuntu-only CI step).

Github-Issue: #1776

Author: maxisbey

src/mcp/server/session.py

@@ -474,7 +474,7 @@ async def send_progress_notification(
             related_request_id,
         )
 
-    async def send_resource_list_changed(self) -> None:  # pragma: no cover
+    async def send_resource_list_changed(self) -> None:
         """Send a resource list changed notification."""
         await self.send_notification(types.ResourceListChangedNotification())