Remove the vitess-mixin

[dbussink]

Description

Based on the discussion in #16613, this removes the vitess-mixin directory. It's currently not maintained, it causes issues with security alerts etc. and none of the currently active Vitess maintainers know how it works or use it.

Related Issue(s)

#16613

Checklist

• "Backport to:" labels have been added if this change should be back-ported to release branches
• If this change is to be back-ported to previous releases, a justification is included in the PR description
• Tests were added or are not required
• Did the new or modified tests pass consistently locally and on CI?
• Documentation was added or is not required

[vitess-bot]

Review Checklist

Hello reviewers! 👋 Please follow this checklist when reviewing this Pull Request.

General

• Ensure that the Pull Request has a descriptive title.
• Ensure there is a link to an issue (except for internal cleanup and flaky test fixes), new features should have an RFC that documents use cases and test cases.

Tests

• Bug fixes should have at least one unit or end-to-end test, enhancement and new features should have a sufficient number of tests.

Documentation

• Apply the release notes (needs details) label if users need to know about this change.
• New features should be documented.
• There should be some code comments as to why things are implemented the way they are.
• There should be a comment at the top of each new or modified test to explain what the test does.

New flags

• Is this flag really necessary?
• Flag names must be clear and intuitive, use dashes (-), and have a clear help text.

If a workflow is added or modified:

• Each item in Jobs should be named in order to mark it as required.
• If the workflow needs to be marked as required, the maintainer team must be notified.

Backward compatibility

• Protobuf changes should be wire-compatible.
• Changes to _vt tables and RPCs need to be backward compatible.
• RPC changes should be compatible with vitess-operator
• If a flag is removed, then it should also be removed from vitess-operator and arewefastyet, if used there.
• vtctl command output order should be stable and awk-able.

[mattlord]

Thanks! ❤️

[frouioui]

The golang-upgrade tool must be updated too so it does not try to update vitess-mixin

I commented why just above

[codecov]

Codecov Report

Attention: Patch coverage is 0% with 1 line in your changes missing coverage. Please review.

Project coverage is 68.92%. Comparing base (a54d5ec) to head (f30c5ee).
Report is 3 commits behind head on main.

Files	Patch %	Lines
go/tools/go-upgrade/go-upgrade.go	0.00%	1 Missing ⚠️

Additional details and impacted files

@@            Coverage Diff             @@
##             main   #16657      +/-   ##
==========================================
- Coverage   68.93%   68.92%   -0.02%     
==========================================
  Files        1562     1562              
  Lines      200767   200767              
==========================================
- Hits       138407   138378      -29     
- Misses      62360    62389      +29     

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[dbussink]

The golang-upgrade tool must be updated too so it does not try to update vitess-mixin

Done!