Remove aperture change callback

[DominicOram]

Fixes #849

Instructions to reviewer on how to test:

1. Confirm tests still pass and all references to aperture change callback have been removed

Checks for reviewer

• Would the PR title make sense to a user on a set of release notes

[codecov]

Codecov Report

All modified and coverable lines are covered by tests ✅

Project coverage is 87.56%. Comparing base (6d235fc) to head (0949568).
Report is 1 commits behind head on main.

Additional details and impacted files

@@            Coverage Diff             @@
##             main     #852      +/-   ##
==========================================
+ Coverage   87.33%   87.56%   +0.23%     
==========================================
  Files         104      104              
  Lines        6995     7109     +114     
==========================================
+ Hits         6109     6225     +116     
+ Misses        886      884       -2     

Components	Coverage Δ
i24 SSX	73.95% <ø> (ø)
hyperion	96.36% <100.00%> (+0.02%)	⬆️
other	96.56% <ø> (+0.32%)	⬆️