AppProjects don't check all namespaces before finalizing deletion

[sthomson-wyn]

Checklist:

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

Describe the bug

If the resources finalizer is used on an AppProject, the application controller doesn't check all namespaces for existing Applications before finalizing deletion

To Reproduce

• create AppProject in default argocd namespace, with resources finalizer
• create Application in another namespace, under the aforementioned AppProject
• Delete the AppProject
• The Application is left hanging

Expected behavior

The AppProject waits for all Applications to delete before removing the finalizer

Screenshots

Version

argocd: v2.9.3+6eba5be.dirty
  BuildDate: 2023-12-02T00:36:55Z
  GitCommit: 6eba5be864b7e031871ed7698f5233336dfe75c7
  GitTreeState: dirty
  GoVersion: go1.21.4
  Compiler: gc
  Platform: linux/amd64
argocd-server: v2.10.2+fcf5d8c

The problem code appears to be here: https://github.com/argoproj/argo-cd/blob/ee9b38fe5ce15ce72ca57cdf16b0addbe2b0a27a/controller/appcontroller.go#L1015 only the default namespace is checked for Applications

[yyzxw]

/assign