hw-enablement: Focus stepper direction on v2.6 hardware is flipped

[ethanjli]

Describe the bug
@tpollina reports that the v2.6 hardware has a PCB assembly error which caused the connector for the focusing stepper motors to be flipped. As a result, focusing "up" moves the sample stage closer to the camera while "down" moves the sample stage away from the camera; this behavior is opposite to the behavior in the previous hardware versions.

Expected behavior
Pressing the focus "up" button should move the sample stage in the same direction regardless of hardware version.

Additional context
This problem, along with a potential software workaround for the hardware bug, was discussed in the 2023-10-26 PlanktoScope software taskforce meeting.