Add test forgotten from #628

[DominicOram]

I wrote this at the time I wrote #628 but forgot to add it

Instructions to reviewer on how to test:

1. Confirm new test passes

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]

Tests failing here are also failing on main so merging anyway