[epilogue] Fix v3 scheduler incompatibility with epilogue (#8458)

Was caused by checking assignability like`Protobuf<Scheduler,
ProtoMessage>` instead of `Protobuf<Scheduler, ? extends
ProtoMessage<?>>`

This epilogue bug would have also applied to other protobuf-serializable
types

commandsv3/src/test/java/org/wpilib/command3/epilogue/SchedulerIsLoggableWithEpilogue.java

@@ -0,0 +1,16 @@
+// Copyright (c) FIRST and other WPILib contributors.
+// Open Source Software; you can modify and/or share it under the terms of
+// the WPILib BSD license file in the root directory of this project.
+
+package org.wpilib.command3.epilogue;
+
+import org.wpilib.command3.Scheduler;
+import org.wpilib.epilogue.Logged;
+
+// This class will fail to compile if m_scheduler is not considered loggable
+// Note that this assumes epilogue is set up correctly.
+@Logged
+public class SchedulerIsLoggableWithEpilogue {
+  @Logged(name = "Scheduler (logged via protobuf)")
+  private final Scheduler m_scheduler = Scheduler.createIndependentScheduler();
+}