fix: Use GITHUB_REF to retrieve tag

[crazy-max]

Closes #238

Use GITHUB_REF to retrieve tag before checking the most recent tag.

[codecov]

Codecov Report

Merging #239 into master will decrease coverage by 0.26%.
The diff coverage is 87.50%.

@@            Coverage Diff             @@
##           master     #239      +/-   ##
==========================================
- Coverage   89.02%   88.76%   -0.27%     
==========================================
  Files           4        4              
  Lines          82       89       +7     
  Branches       12       16       +4     
==========================================
+ Hits           73       79       +6     
  Misses          5        5              
- Partials        4        5       +1     

Impacted Files	Coverage Δ
src/git.ts	79.16% <87.50%> (+2.69%)	⬆️

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