Delete CoreFeatures::enableReportEventPaintTime

Summary:
I'm deleting CoreFeatures::enableReportEventPaintTime because this feature flag has never been enabled since it was created 8+ months ago

changelog: [internal] internal

Differential Revision: D60134872

packages/react-native/ReactCommon/react/renderer/observers/events/EventPerformanceLogger.cpp

@@ -141,12 +141,6 @@ void EventPerformanceLogger::onEventProcessingEnd(EventTag tag) {
     auto& entry = it->second;
     entry.processingEndTime = timeStamp;
 
-    if (ReactNativeFeatureFlags::enableReportEventPaintTime()) {
-      // If reporting paint time, don't send the entry just yet and wait for the
-      // mount hook callback to be called
-      return;
-    }
-
     const auto& name = entry.name;
 
     performanceEntryReporter->logEventEntry(
@@ -163,10 +157,6 @@ void EventPerformanceLogger::onEventProcessingEnd(EventTag tag) {
 void EventPerformanceLogger::shadowTreeDidMount(
     const RootShadowNode::Shared& /*rootShadowNode*/,
     double mountTime) noexcept {
-  if (!ReactNativeFeatureFlags::enableReportEventPaintTime()) {
-    return;
-  }
-
   auto performanceEntryReporter = performanceEntryReporter_.lock();
   if (performanceEntryReporter == nullptr) {
     return;

packages/react-native/ReactCommon/react/renderer/scheduler/Scheduler.cpp

@@ -151,10 +151,6 @@ Scheduler::Scheduler(
   removeOutstandingSurfacesOnDestruction_ = reactNativeConfig_->getBool(
       "react_fabric:remove_outstanding_surfaces_on_destruction_ios");
 #endif
-
-  if (ReactNativeFeatureFlags::enableReportEventPaintTime()) {
-    uiManager->registerMountHook(*eventPerformanceLogger_);
-  }
 }
 
 Scheduler::~Scheduler() {