Add logic to stop waiting on pin if robot raises pin not found error

[DominicOram]

Fixes DiamondLightSource/hyperion#1446 and fixes DiamondLightSource/hyperion#1450

Instructions to reviewer on how to test:

1. Confirm tests pass

Checks for reviewer

• Would the PR title make sense to a scientist on a set of release notes
• If a new device has been added does it follow the standards
• If changing the API for a pre-existing device, ensure that any beamlines using this device have updated their Bluesky plans accordingly
• Have the connection tests for the relevant beamline(s) been run via dodal connect ${BEAMLINE}

[DominicOram]

@coretl and @callumforrester, I'm particularly interested in your thoughts on pin_mounted_or_no_pin_found. Is this the best way to solve the problem? Are there helper functions we can put into ophyd-async for this? Maybe an observe_multiple_values for getting all the updates from multiple signals?

[coretl]

I think you've done this in the most concise way at present, but I think you're right about adding a helper to ease this, maybe something like:

    async def pin_mounted_or_no_pin_found(self):
        async for signal, value in observe_signals_value(self.error_code, self.goinio_pin_sensor):
            if signal is self.error_code and value == self.NO_PIN_ERROR_CODE:
                # We didn't get a pin
                raise RobotLoadFailed(self.NO_PIN_ERROR_CODE, "Pin was not detected")
            elif signal is self.goinio_pin_sensor and value == PinMounted.PIN_MOUNTED:
                # We did get a pin
                break

[DominicOram]

Thanks @coretl, that's exactly the sort of thing I was thinking. I've made bluesky/ophyd-async#402. I will leave this as is to maintain velocity on hyperion but will pull the ophyd-async issue into our next sprint

[rtuck99]

These asserts are never called

[rtuck99]

I don't understand what these sleeps are for - you don't enter the coroutine until await is called on it.

[rtuck99]

Looks good now