fix cert.URIs

[cpanato]

Summary

• fix cert.URIs
  It is generating "https://gitlab.com/cpanato/testing-cosign/@/refs/heads/main" and that should be "https://gitlab.com/cpanato/testing-cosign@refs/heads/main" for example

[haydentherapper]

Do you have any other testing to do or other issues that need to get fixed? Otherwise we can cut 1.3.1 with the fix

[codecov]

Codecov Report

Merging #1144 (a285bab) into main (13dcf39) will not change coverage.
The diff coverage is 100.00%.

@@           Coverage Diff           @@
##             main    #1144   +/-   ##
=======================================
  Coverage   56.02%   56.02%           
=======================================
  Files          50       50           
  Lines        2904     2904           
=======================================
  Hits         1627     1627           
  Misses       1133     1133           
  Partials      144      144           

Impacted Files	Coverage Δ
pkg/identity/gitlabcom/principal.go	62.61% <100.00%> (ø)

[cpanato]

Do you have any other testing to do or other issues that need to get fixed? Otherwise we can cut 1.3.1 with the fix

Dont think we have, just a few improvements in the tests but that will take more time, and will apply for GitHub and others as well

[cpanato]

sounds good a patch cut, thanks