fix(distribution): Backport distribution fix 'add bounded concurrency for tag lookup and untag

[thcdrt]

Comprehensive Summary of your change

Hello,

Investigating about a garbage collection taking months/years to finish, I checked the GC logs and found out that the manifest deletion always took ~30s.
So I asked if some people had the same issue on slack and I found the issue #12948 talking about it and linking to a docker distribution PR fixing the issue.
Problem is that it will be probably only be released on Distribution v3 while this version is still in working state after years of work, that's why I decided to cherry-pick the fix distribution/distribution#4329 written by @microyahoo to improve garbage collection manifest deletion.

I tested the fix, and I went from 30s to ~7s to delete a manifest.

A new configuration has been added on distribution configuration side to configure tag deletion concurrency limit, by default it's set to runtime.GOMAXPROCS(0), so it's working without having to modify docker distribution configuration (no need to modify the Helm Chart).

Issue being fixed

Fixes #12948

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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"
• Accepted the DCO. Commits without the DCO will delay acceptance.
• 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.

[codecov]

Codecov Report

All modified and coverable lines are covered by tests ✅

Project coverage is 46.22%. Comparing base (c8c11b4) to head (664a012).
Report is 390 commits behind head on main.

Additional details and impacted files

@@            Coverage Diff             @@
##             main   #21652      +/-   ##
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+ Coverage   45.36%   46.22%   +0.86%     
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  Files         244      247       +3     
  Lines       13333    13883     +550     
  Branches     2719     2875     +156     
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+ Hits         6049     6418     +369     
- Misses       6983     7128     +145     
- Partials      301      337      +36     

Flag	Coverage Δ
unittests	46.22% <ø> (+0.86%)	⬆️

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see 491 files with indirect coverage changes

[Vad1mo]

@thcdrt, did you try using Distribution v3?

[thcdrt]

No I didn't want to take the risk as it's not released yet.