Update src/libraries/System.IO.FileSystem.Watcher/src/System/IO/FileSystemWatcher.SunOS.cs

Co-authored-by: Copilot <175728472+Copilot@users.noreply.github.com>

Author: gwr

src/libraries/System.IO.FileSystem.Watcher/src/System/IO/FileSystemWatcher.SunOS.cs

@@ -56,8 +56,8 @@
 // 5. Cleanup (StopRaisingEvents):
 //    - Cancel token
 //    - Send port_send to wake up port_get
-//    - Wait for event thread to exit
-//    - Clean up all resources
+//    - Return without waiting; event thread exits asynchronously
+//    - Clean up resources as shutdown completes
 //
 // PortAssociate Strategy:
 //