ci: improve image handling

[cyphar]

A few patches to improve image handling with our CI.

Signed-off-by: Aleksa Sarai [email protected]

[codecov-commenter]

Codecov Report

Merging #452 (49accc6) into main (de9ad94) will decrease coverage by 0.03%. The diff coverage is n/a.

:exclamation: Current head 49accc6 differs from pull request most recent head 37c828e. Consider uploading reports for the commit 37c828e to get more accurate results

:mega: This organization is not using Codecov’s GitHub App Integration. We recommend you install it so Codecov can continue to function properly for your repositories. Learn more

Additional details and impacted files

@@            Coverage Diff             @@
##             main     #452      +/-   ##
==========================================
- Coverage   46.59%   46.57%   -0.03%     
==========================================
  Files          60       60              
  Lines        4872     4872              
==========================================
- Hits         2270     2269       -1     
- Misses       2338     2339       +1     
  Partials      264      264              

see 1 file with indirect coverage changes

[cyphar]

LGTM.