chore: update GitHub branch references to use HEAD

[thinkingserious]

Checklist

• I acknowledge that all my contributions will be made under the project's license

[codecov]

Codecov Report

Merging #128 into main will not change coverage.
The diff coverage is n/a.

@@            Coverage Diff            @@
##               main     #128   +/-   ##
=========================================
  Coverage     49.28%   49.28%           
  Complexity       38       38           
=========================================
  Files             5        5           
  Lines           211      211           
  Branches         16       16           
=========================================
  Hits            104      104           
  Misses          103      103           
  Partials          4        4           

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