Deployment scenario upgrade from 1.5/1.4 to main fails on workload cluster creation with "The directory passed does not contains a workload cluster kustomization."

Summary

Example: https://gitlab.com/sylva-projects/sylva-core/-/jobs/12835751557

Also related to #3357 (closed)

Steps to reproduce

Use ☁️capm3 🚀rke2 🎬upgrade-from-release-1.5 🛠️ha 🐧suse on main

What is the current bug behavior?

Deployment fails

What is the expected correct behavior?

Relevant logs and/or screenshots

$ ./apply-workload-cluster.sh ${ENV_PATH}
🔎 Validate input files
00:01
The directory passed does not contains a workload cluster kustomization.

Possible fix

Regression is due to !6444 (merged)