clean up

com.unity.perception/Runtime/Randomization/Scenarios/PerceptionScenario.cs

         /// </summary>
         MetricDefinition m_IterationMetricDefinition;
 
-        /// <summary>
-        /// The scriptable render pipeline hook used to capture perception data skips the first frame of the simulation
-        /// when running locally, so this flag is used to track whether the first frame has been skipped yet.
-        /// </summary>
-        protected bool m_SkippedFirstFrame;
-
         /// <inheritdoc/>
         protected override bool isScenarioReadyToStart => Time.frameCount >= 1;