Fix rotation plan tests

[DominicOram]

To test:

1. Confirm that unit tests now pass

[codecov]

Codecov Report

Merging #862 (75780ce) into main (6a8be31) will increase coverage by 0.01%.
Report is 8 commits behind head on main.
The diff coverage is 100.00%.

@@            Coverage Diff             @@
##             main     #862      +/-   ##
==========================================
+ Coverage   94.62%   94.63%   +0.01%     
==========================================
  Files          43       43              
  Lines        2120     2124       +4     
==========================================
+ Hits         2006     2010       +4     
  Misses        114      114              

Files Changed	Coverage Δ
src/artemis/experiment_plans/full_grid_scan.py	100.00% <ø> (ø)
...rtemis/experiment_plans/oav_grid_detection_plan.py	100.00% <100.00%> (ø)
src/artemis/experiment_plans/rotation_scan_plan.py	100.00% <100.00%> (ø)
...plan_specific/grid_scan_with_edge_detect_params.py	96.00% <100.00%> (+0.08%)	⬆️

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