Bump golang from 1.20-alpine3.18 to 1.21-alpine3.18

[dependabot[bot]]

Bumps golang from 1.20-alpine3.18 to 1.21-alpine3.18.

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[codecov[bot]]

Codecov Report

Merging #10 (5d0f4c6) into main (6ddeb21) will not change coverage. Report is 2 commits behind head on main. The diff coverage is n/a.

:exclamation: Current head 5d0f4c6 differs from pull request most recent head 9356dfd. Consider uploading reports for the commit 9356dfd to get more accurate results

@@           Coverage Diff           @@
##             main      #10   +/-   ##
=======================================
  Coverage   54.84%   54.84%           
=======================================
  Files          22       22           
  Lines        1218     1218           
=======================================
  Hits          668      668           
  Misses        488      488           
  Partials       62       62