fix(argo-workflows): Allow controller to edit workflowartifactgctask's finalizers

[kiblik]

Reason: I wanted to use ArtifactGC but opperation was failing with

time="2026-02-20T20:01:48.730Z" level=error msg="failed to GC artifacts" error="failed to create pod: pods \"...\" is forbidden: cannot set blockOwnerDeletion if an ownerReference refers to a resource you can't set finalizers on: , <nil>" namespace=... workflow=...

I locally tested adding the mentioned permission, and it looks it fix the issue.

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Checklist:

• I have bumped the chart version according to versioning
• I have updated the documentation according to documentation
• I have updated the chart changelog with all the changes that come with this pull request according to changelog.
• Any new values are backwards compatible and/or have sensible default.
• I have signed off all my commits as required by DCO.
• I have created a separate pull request for each chart according to pull requests
• My build is green (troubleshooting builds).

[tico24]

This is not upstream so should not be added to the Helm chart

https://github.com/argoproj/argo-workflows/blob/main/manifests/cluster-install-no-crds/workflow-controller-rbac/workflow-controller-clusterrole.yaml#L45