Update CI for setup-gap@v3

[stertooy]

Updates the inputs of the setup-gap action to releases instead of branches, and moves the GAP_PKGS_TO_CLONE: "alnuth" input to a separate step in the workflow.

[codecov]

Codecov Report

✅ All modified and coverable lines are covered by tests.
✅ Project coverage is 55.82%. Comparing base (577af62) to head (7d106fa).
⚠️ Report is 1 commits behind head on master.

Additional details and impacted files

@@            Coverage Diff             @@
##           master     #109      +/-   ##
==========================================
+ Coverage   55.79%   55.82%   +0.03%     
==========================================
  Files          87       87              
  Lines       12678    12678              
==========================================
+ Hits         7074     7078       +4     
+ Misses       5604     5600       -4     

see 2 files with indirect coverage changes

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[fingolfin]

Thanks

[fingolfin]

Needs conflict resolution now