Unmount "ReaderNavBarDesktop" on exit

Re-rendering the component isn't too expensive and unmounting it improves the re-rendering caused by page changes since it doesn't get updated.

This removes ~7ms on a "current page" state update and ~25ms caused by the chapter update due to the "last read page" change

src/modules/reader/components/overlay/navigation/desktop/ReaderNavBarDesktop.tsx

@@ -100,6 +100,9 @@ const BaseReaderNavBarDesktop = ({
             variant={isStaticNav ? 'permanent' : 'persistent'}
             open={isVisible || isStaticNav}
             transitionDuration={drawerTransitionDuration}
+            SlideProps={{
+                unmountOnExit: true,
+            }}
             PaperProps={{
                 ref: (ref: HTMLDivElement | null) => setNavBarElement(ref),
             }}