Add one-time workflow to push an image to ghcr.io

[imjasonh]

This will hopefully fix our permanently failing GHCR auth test. 🤞

After we run it and have an image in the repo, we can delete the workflow, unless we want to keep it around for some reason.

[codecov-commenter]

Codecov Report

Merging #1281 (1110777) into main (33725d2) will not change coverage.
The diff coverage is n/a.

❗ Current head 1110777 differs from pull request most recent head 11330dc. Consider uploading reports for the commit 11330dc to get more accurate results

@@           Coverage Diff           @@
##             main    #1281   +/-   ##
=======================================
  Coverage   74.01%   74.01%           
=======================================
  Files         112      112           
  Lines        8374     8374           
=======================================
  Hits         6198     6198           
  Misses       1573     1573           
  Partials      603      603           

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