[DRAFT/Conversation] gpg: raise a clearer error when a key to install is invalid

[lengau]

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[codecov[bot]]

Codecov Report

Merging #44 (920b4ce) into main (387b401) will decrease coverage by 0.17%. The diff coverage is 66.66%.

:exclamation: Current head 920b4ce differs from pull request most recent head af43f25. Consider uploading reports for the commit af43f25 to get more accurate results

@@            Coverage Diff             @@
##             main      #44      +/-   ##
==========================================
- Coverage   82.65%   82.48%   -0.17%     
==========================================
  Files          12       12              
  Lines         663      668       +5     
  Branches      148      149       +1     
==========================================
+ Hits          548      551       +3     
- Misses         85       86       +1     
- Partials       30       31       +1     

Impacted Files	Coverage Δ
craft_archives/repo/apt_key_manager.py	95.95% <66.66%> (-1.92%)	:arrow_down:

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[lengau]

No longer relevant