fix: Support kustomize v5 labels transformer. Fixes #3105

[int128]

This resolves #3105.

It contains the following commits:

• Cherry-pick @dlemfh's original commit: dlemfh@31a8971
• Rename it as @zachaller's comment: Breaking changes when using kustomize v5 with rollout-transform.yaml #3105 (comment)
• Add the doc

I have tested this change using below kustomization.yaml.

apiVersion: kustomize.config.k8s.io/v1beta1
kind: Kustomization
configurations:
# https://github.com/argoproj/argo-rollouts/issues/3105#issuecomment-1762856207
- https://raw.githubusercontent.com/int128/argo-rollouts/b7d5d5398629f7452415a90ac41940694652ceb4/docs/features/kustomize/rollout-transform-kustomize-v5.yaml
labels:
- includeTemplates: true
  pairs:
    tags.datadoghq.com/service: example

---

Checklist:

• Either (a) I've created an enhancement proposal and discussed it with the community, (b) this is a bug fix, or (c) this is a chore.
• The title of the PR is (a) conventional with a list of types and scopes found here, (b) states what changed, and (c) suffixes the related issues number. E.g. "fix(controller): Updates such and such. Fixes #1234".
• I've signed my commits with DCO
• I have written unit and/or e2e tests for my change. PRs without these are unlikely to be merged.
• My builds are green. Try syncing with master if they are not.
• My organization is added to USERS.md.

[sonarqubecloud]

Quality Gate passed

Issues
0 New issues
0 Accepted issues

Measures
0 Security Hotspots
0.0% Coverage on New Code
0.0% Duplication on New Code

See analysis details on SonarCloud

[int128]

Diff to rollout-transform.yaml

--- docs/features/kustomize/rollout-transform.yaml	2024-08-07 18:33:37
+++ docs/features/kustomize/rollout-transform-kustomize-v5.yaml	2024-08-07 18:49:48
@@ -203,6 +203,11 @@
   create: false
   kind: Rollout

+templateLabels:
+- path: spec/template/metadata/labels
+  create: true
+  kind: Rollout
+
 # https://github.com/kubernetes-sigs/kustomize/blob/master/api/konfig/builtinpluginconsts/commonannotations.go
 commonAnnotations:
 - path: spec/template/metadata/annotations

[dlemfh]

Awesome!

[github-actions]

Published E2E Test Results

  4 files    4 suites   3h 32m 29s ⏱️
111 tests  98 ✅  6 💤  7 ❌
462 runs  420 ✅ 24 💤 18 ❌

For more details on these failures, see this check.

Results for commit b7d5d53.

[github-actions]

Published Unit Test Results

2 176 tests   2 176 ✅  2m 55s ⏱️
  119 suites      0 💤
    1 files        0 ❌

Results for commit b7d5d53.

[codecov]

Codecov Report

All modified and coverable lines are covered by tests ✅

Project coverage is 84.26%. Comparing base (827ce59) to head (b7d5d53).
Report is 69 commits behind head on master.

Additional details and impacted files

@@            Coverage Diff             @@
##           master    #3775      +/-   ##
==========================================
+ Coverage   84.24%   84.26%   +0.02%     
==========================================
  Files         154      154              
  Lines       18022    18022              
==========================================
+ Hits        15182    15187       +5     
+ Misses       1998     1995       -3     
+ Partials      842      840       -2     

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