Add nullptr guard in record_runtime_stats_ for scheduler items

esphome/core/component.cpp

@@ -521,6 +521,8 @@ WarnIfComponentBlockingGuard::warn_blocking(Component *component, uint32_t block
 
 #ifdef USE_RUNTIME_STATS
 void WarnIfComponentBlockingGuard::record_runtime_stats_() {
+  if (this->component_ == nullptr)
+    return;
   uint32_t duration_us = micros() - this->started_us_;
   this->component_->runtime_stats_.record_time(duration_us);
 }