Remove -e from private requirements for k8s

[robrap]

We don't think we need -e for any of our private requirement installs in k8s:

• https://github.com/edx/edx-internal/blob/master/argocd/applications/edxapp-lms/requirements/private_requirements.txt

This ticket is about removing them from the k8s deployment to see what happens. The thing to be most careful of is that we don't break the k8s kafka-consumer deployment, which is actively in use in Production.