Remove comments and small things from repo that mention roboRIO (#9020)

The RoboRIO classes need to be fixed up, those are huge.

wpilibj/src/main/java/org/wpilib/framework/RobotBase.java

@@ -62,7 +62,7 @@ public abstract class RobotBase implements AutoCloseable {
           }
 
           @Override
-          public boolean isRoboRIO() {
+          public boolean isSystemcore() {
             return !RobotBase.isSimulation();
           }
         };