fix(indexer): extract Apps from Promotion directives

[hiddeco]

Variation of #2593.

As noted in the // TODO, I would like at some point for us to not treat certain directives as "special" — but from a functional point of view, that's not a strict requirement at this point.

I did have to move the indexers out of kubeclient, to get around a cyclic import.

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[codecov]

Codecov Report

Attention: Patch coverage is 46.47887% with 38 lines in your changes missing coverage. Please review.

Project coverage is 50.98%. Comparing base (0e79db7) to head (6f38edf).

Files with missing lines	Patch %	Lines
internal/indexer/indexer.go	50.00%	11 Missing and 1 partial ⚠️
internal/controller/stages/stages.go	61.90%	8 Missing ⚠️
internal/api/kubernetes/client.go	0.00%	6 Missing ⚠️
cmd/controlplane/garbage_collector.go	0.00%	3 Missing ⚠️
internal/controller/stages/watches.go	0.00%	3 Missing ⚠️
internal/api/option/auth.go	0.00%	2 Missing ⚠️
cmd/controlplane/webhooks.go	0.00%	1 Missing ⚠️
internal/api/list_project_events_v1alpha1.go	0.00%	1 Missing ⚠️
internal/api/list_promotions_v1alpha1.go	0.00%	1 Missing ⚠️
internal/controller/promotions/promotions.go	0.00%	1 Missing ⚠️

Additional details and impacted files

@@            Coverage Diff             @@
##             main    #2620      +/-   ##
==========================================
- Coverage   50.98%   50.98%   -0.01%     
==========================================
  Files         282      282              
  Lines       21015    21039      +24     
==========================================
+ Hits        10714    10726      +12     
- Misses       9630     9641      +11     
- Partials      671      672       +1     

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[akuitybot]

Successfully created backport PR for release-0.9:

• chore(backport release-0.9): fix(indexer): extract Apps from Promotion directives #2621