Auto DevOps: ensure_namespace fails for all projects and clusters with "Please enter username"

Summary

This https://forum.gitlab.com/t/gitlab-com-autodevops-deployment-failing-with-please-enter-username/20879 is happening on all our projects and clusters.

This prevents deployment to our production cluster and so for us is critical.

Steps to reproduce

Run any autodevops pipeline with a Kubernetes cluster configuration that was added before the problem occurred. I'm sorry, I don't know when that is.

Example Project

I only have private projects that exhibit this behaviour, maybe some of the users at https://forum.gitlab.com/t/gitlab-com-autodevops-deployment-failing-with-please-enter-username/20879 have examples

What is the current bug behavior?

ensure_namespace fails with

$ ensure_namespace
Please enter Username: Please enter Username: Please enter Username: error: EOF
Please enter Username: Please enter Username: error: EOF
ERROR: Job failed: exit code 1

What is the expected correct behavior?

ensure_namespace succeeds

Relevant logs and/or screenshots

See above

Output of checks

This bug happens on GitLab.com

Possible fixes

A workaround is posted at https://forum.gitlab.com/t/gitlab-com-autodevops-deployment-failing-with-please-enter-username/20879, but this is manual and tedious for large numbers of projects and clusters. We can't really apply this easily for our production projects and cluster.