fix: xcode 26.4 builds fail

[g4rb4g3]

This PR fixes the failing builds with Xcode 26.4 by bumping fmt.
facebook/react-native#56099

[github-actions]

node_modules/react-native/React/CoreModules/RCTTiming.h:undefined

Removal of RCTFrameUpdateObserver from the interface may break expected frame update notifications (e.g. didUpdateFrame:), potentially causing logic errors.

[github-actions]

node_modules/react-native/React/CoreModules/RCTTiming.mm:undefined

The NSTimer (_timer) scheduled in setup is never invalidated in invalidate, risking that it will continue firing after the object is disposed. Consider adding:

  [_timer invalidate];
  _timer = nil;
  _bridge = nil;

[github-actions]

node_modules/react-native/React/CoreModules/RCTTiming.mm:undefined

Removal of the call to stopTimers in appDidMoveToBackground may allow timers to continue running while the app is in the background, potentially leading to unnecessary resource usage or battery drain.

[github-actions]

The changes remove timer management functions and observer conformance without replacing their logic, which can lead to unexpected timer behavior and potential resource leaks.