Avoid disposing invalid handle

Author: BrennanConroy

src/Servers/HttpSys/src/NativeInterop/RequestQueue.cs

@@ -180,10 +180,13 @@ public void Dispose()
 
         _disposed = true;
 
+        // Close the request queue handle first to cancel any pending IO operations.
+        // This must happen before disposing BoundHandle, as pending operations need
+        // to be cancelled and cleaned up using the BoundHandle.
         PInvoke.HttpCloseRequestQueue(Handle);
 
         BoundHandle.Dispose();
-        Handle.Dispose();
+        Handle.SetHandleAsInvalid();
     }
 
     private void CheckDisposed()