UI/AppKit: Set WC's max FPS to the max FPS of the current screen

Author: https://github.com/Lubrsi
Commit: b0d97c991f
Pull-request: https://github.com/LadybirdBrowser/ladybird/pull/5606
Reviewed-by: https://github.com/Psychpsyo
Reviewed-by: https://github.com/kalenikaliaksandr

UI/AppKit/Interface/LadybirdWebView.h

@@ -70,6 +70,7 @@
 
 - (void)handleResize;
 - (void)handleDevicePixelRatioChange;
+- (void)handleDisplayRefreshRateChange;
 - (void)handleVisibility:(BOOL)is_visible;
 
 - (void)setPreferredColorScheme:(Web::CSS::PreferredColorScheme)color_scheme;