fix: The onResize callback is no longer incorrectly called with the…

… same values.

The same memoisation applied to the hook response's width and height
should've applied to the onResize callback as well, but it didn't.

This is now fixed, which means that even if the RO reports a change,
the onResize callback will only be called if there's an actual change
to report after the rounding function was applied to the reported values.

README.md

@@ -275,4 +275,3 @@ The same technique can also be used to provide any of your preferred ResizeObser
 ## License
 
 MIT
-