chore: remove argocd-cm plugin support

[crenshaw-dev]

Fixes #8117

[codecov]

Codecov Report

Patch coverage: 4.76% and project coverage change: -0.03 ⚠️

Comparison is base (150a184) 49.64% compared to head (812944b) 49.61%.

Additional details and impacted files

@@            Coverage Diff             @@
##           master   #13755      +/-   ##
==========================================
- Coverage   49.64%   49.61%   -0.03%     
==========================================
  Files         256      256              
  Lines       43914    43800     -114     
==========================================
- Hits        21800    21733      -67     
+ Misses      19958    19934      -24     
+ Partials     2156     2133      -23     

Impacted Files	Coverage Δ
cmd/argocd/commands/admin/settings.go	67.74% <ø> (+0.24%)	⬆️
cmd/argocd/commands/app.go	21.81% <0.00%> (+0.01%)	⬆️
controller/state.go	72.40% <ø> (+0.62%)	⬆️
reposerver/repository/repository.go	59.26% <0.00%> (-1.49%)	⬇️
util/argo/argo.go	66.45% <ø> (-0.13%)	⬇️
util/settings/settings.go	50.00% <ø> (ø)
server/application/application.go	49.77% <100.00%> (+0.18%)	⬆️

... and 2 files with indirect coverage changes

☔ View full report in Codecov by Sentry.
📢 Do you have feedback about the report comment? Let us know in this issue.

[todaywasawesome]

I worry about this one because it's such a widely used feature. Could be perhaps just add a deprecation warning for a few versions before removing?

[crenshaw-dev]

@todaywasawesome it's been deprecated since 2.5, and we've pushed removal twice. 😆 https://argo-cd.readthedocs.io/en/latest/operator-manual/upgrading/2.4-2.5/#argocd-cm-plugins-cmps-are-deprecated

[todaywasawesome]

You can always count on me to ask the critical questions 🥴

[crenshaw-dev]

It's a fair point though. I fully expect people will be on this thread two years from now saying "aw man, why did y'all do this, I'm just upgrading from 1.9, this sucks." :-P

[pasha-codefresh]

@crenshaw-dev could you please fix conflicts?

[crenshaw-dev]

@pasha-codefresh this is ready for another look

[crenshaw-dev]

@pasha-codefresh wanna glance at the e2e test fixes?

[pasha-codefresh]

Thank you