Switch Pulp to basic HTTP auth

We are currently using cert + key token, and we should use basic HTTP auth. 

We should be able to generate them here 
https://access.redhat.com/terms-based-registry/

And then allow them here
https://internal.console.redhat.com/api/pulp-mgmt/core/group/7/change/

There is no rush in the switch. Q1 is great, but deadline is end of 2026.