Extend AWS ECR regex for c2s support

[ethanchowell]

Thank you for contributing to Harbor!

Comprehensive Summary of your change

This PR extends the ecr regex check for c2s regions that don't follow the amazonaws domain convention.

Issue being fixed

Fixes #(issue)

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• Well Written Title and Summary of the PR
• Label the PR as needed. "release-note/ignore-for-release, release-note/new-feature, release-note/update, release-note/enhancement, release-note/community, release-note/breaking-change, release-note/docs, release-note/infra, release-note/deprecation"
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• Made sure tests are passing and test coverage is added if needed.
• Considered the docs impact and opened a new docs issue or PR with docs changes if needed in website repository.

[MinerYang]

Hi @ethanchowell ,

Thanks for your contributions!
Could you help to provide the related official doc for this regex definition if there's any?

Best,
Miner

[ethanchowell]

I'm not aware of any official docs, but can point to the ecr-credential-helper that implements this pattern successfully. Slightly modified of course to account for existing tests within the project.

[chlins]

@ethanchowell Hi, thanks for your contribution, please resolve the DCO failure in CI.

[codecov]

Codecov Report

All modified and coverable lines are covered by tests ✅

Project coverage is 66.24%. Comparing base (c8c11b4) to head (a73e539).
Report is 238 commits behind head on main.

Additional details and impacted files

@@             Coverage Diff             @@
##             main   #20648       +/-   ##
===========================================
+ Coverage   45.36%   66.24%   +20.87%     
===========================================
  Files         244     1045      +801     
  Lines       13333   113501   +100168     
  Branches     2719     2845      +126     
===========================================
+ Hits         6049    75188    +69139     
- Misses       6983    34202    +27219     
- Partials      301     4111     +3810     

Flag	Coverage Δ
unittests	66.24% <100.00%> (+20.87%)	⬆️

Flags with carried forward coverage won't be shown. Click here to find out more.

Files	Coverage Δ
src/pkg/reg/adapter/awsecr/adapter.go	68.62% <100.00%> (ø)

... and 1286 files with indirect coverage changes

[chlins]

Please add length check for rs before this line.

[ethanchowell]

Happy to add it, but shouldn't that always evaluate to true based on the docs for FindStringSubmatch? In the event of no match it would just be nil.