Regression on Managed Namespace Metadata Option

[jonwraymond]

Checklist:

• I've searched in the docs and FAQ for my answer: https://bit.ly/argocd-faq.
• I've included steps to reproduce the bug.
• I've pasted the output of argocd version.

Describe the bug

It looks like this change may have caused a regression that causes a duplicate namespace issue on a single application if a namespace object is has been defined in a manifest along with the managedNamespaceMetadata option enabled of an application. This seems to be related to the argocd.argoproj.io/sync-options": "ServerSideApply=true annotation being applied to namespaces. This causes a resource conflict on the defined namespace object.

The docs here say this should be possible with a namespace object.

To Reproduce

1. Create a namespace kubernetes manifest without server side apply in an application.
2. Enable managedNamespaceMetadata: on an application.

Expected behavior

Merge metadata from managedNamespaceMetadata when a namespace object is defined in manifests. This used to work before version v2.8.4

Workaround*

Remove managedNamespaceMetadata block from application and only use k8s namespace manifest.

Version

v2.8.4