Make sure we enable dev/shm when required

[DominicOram]

Fixes #545

See also DiamondLightSource/dodal#819

To test:

• Confirm test fails on main and passes here

[codecov]

Codecov Report

All modified and coverable lines are covered by tests ✅

Project coverage is 78.18%. Comparing base (4636129) to head (d801dfb).

Additional details and impacted files

@@            Coverage Diff             @@
##             main     #555      +/-   ##
==========================================
- Coverage   78.19%   78.18%   -0.01%     
==========================================
  Files          92       92              
  Lines        6796     6794       -2     
==========================================
- Hits         5314     5312       -2     
  Misses       1482     1482              

Components	Coverage Δ
i24 SSX	57.12% <ø> (ø)
hyperion	96.23% <100.00%> (-0.01%)	⬇️
other	100.00% <ø> (ø)

[olliesilvester]

Given that, right now, we only ever use the gpu results for comparison (rather than actually use them for analysis), I think we should just remove use_cpu_and_gpu_zocalo - we can use use_gpu for this too.

Also would be good to add a comment saying that use_gpu=True means dev/shm is enabled and that a comparison is made between CPU and GPU results

[DominicOram]

As discussed, naming is confusing, we should removeuse_gpu for now and rename use_cpu_and_gpu_zocalo to compare_cpu_and_gpu_results then only turn dev/shm on when compare_cpu_and_gpu_results is True