Ship new differ on iOS

Summary:
While we are still waiting for Android results, we can safely ship this on iOS.

Changelog: [Internal]

Reviewed By: fkgozali

Differential Revision: D28542478

fbshipit-source-id: 2673cc4bea0edbc7e4211be7bfec9779205d721b

Author: JoshuaGross

ReactCommon/react/renderer/scheduler/Scheduler.cpp

@@ -130,8 +130,7 @@ Scheduler::Scheduler(
 #else
   removeOutstandingSurfacesOnDestruction_ = reactNativeConfig_->getBool(
       "react_fabric:remove_outstanding_surfaces_on_destruction_ios");
-  enableNewDiffer_ =
-      reactNativeConfig_->getBool("react_fabric:enable_new_differ_h1_2021_ios");
+  enableNewDiffer_ = true;
 #endif
 }