Replace use of Spegel fork with upstream

[phillebaba]

Proposed Changes

This replaces the k3s fork of Spegel with the upstream version. This change can be done as the changes done in the fork have been merged upstream.

Types of Changes

No changes introduced, just a replacement of dependency.

Verification

Rely on existing testing of Spegel integration in k3s.

Testing

Linked Issues

User-Facing Change

Further Comments

An easy way to check the change is to look at the diff between the k3s fork and upstream. The only changes are related to changes that have been done upstream.

https://github.com/XenitAB/spegel/compare/main..k3s-io:spegel:k3s-main

[brandond]

This is awesome, thank you!

[codecov]

Codecov Report

Attention: 16 lines in your changes are missing coverage. Please review.

Comparison is base (de82584) 49.42% compared to head (2f577c8) 42.92%.

Files	Patch %	Lines
pkg/spegel/spegel.go	0.00%	11 Missing ⚠️
pkg/spegel/bootstrap.go	0.00%	5 Missing ⚠️

Additional details and impacted files

@@            Coverage Diff             @@
##           master    #9365      +/-   ##
==========================================
- Coverage   49.42%   42.92%   -6.51%     
==========================================
  Files         151      154       +3     
  Lines       13475    13533      +58     
==========================================
- Hits         6660     5809     -851     
- Misses       5474     6557    +1083     
+ Partials     1341     1167     -174     

Flag	Coverage Δ
e2etests	?
inttests	39.49% <0.00%> (+0.03%)	⬆️
unittests	15.94% <0.00%> (?)

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[brandond]

LGTM, but it looks like there's a conflict. If you're up for a rebase, we're planning to go into code freeze for next week's releases on Monday.

[phillebaba]

@brandond missed the code freeze but i rebased now, and can rebase again later when it is possible to merge. Do you know when that will be possible?

[dereknola]

Code Freeze usually lasts about 2 weeks, so likely towards the end of February.

[brandond]

@phillebaba FYI I might be looking into adding support for mirroring images from all registries, instead of a fixed list - see the thread at #9061 (comment)