Fixed uMp-4 none check

Author: kjy5

src/ephys_link/bindings/ump_4_binding.py

@@ -100,7 +100,7 @@ async def set_position(self, manipulator_id: str, position: Vector4, speed: floa
             raise RuntimeError(error_message)
 
         # Handle empty end position.
-        if not movement.last_pos:  # pyright: ignore [reportUnknownMemberType]
+        if movement.last_pos is None or len(movement.last_pos) == 0:  # pyright: ignore [reportUnknownMemberType]
             error_message = f"Manipulator {manipulator_id} did not reach target position"
             raise RuntimeError(error_message)