merge API stuff into backend

Author: rickwierenga

pylabrobot/arms/backend.py

@@ -57,16 +57,6 @@ class HorizontalAccess:
 class ArmBackend(MachineBackend, metaclass=ABCMeta):
   """Backend for a robotic arm"""
 
-  @abstractmethod
-  async def set_speed(self, speed: float):
-    """Set the speed percentage of the arm's movement (0-100)."""
-    ...
-
-  @abstractmethod
-  async def get_speed(self) -> float:
-    """Get the current speed percentage of the arm's movement."""
-    ...
-
   @abstractmethod
   async def open_gripper(self):
     """Open the arm's gripper."""