Remove enterprise repos before adding new repos

[agross]

• Every removal would trigger "apt update" with the remaining (inaccessible) repos, add an extra update_cache: false.
• https://enterprise.proxmox.com/debian/ceph-quincy is configured on a fresh Proxmox 8.x install.

Closes #290

[lae]

Duplicate of #288, #192, and #96.

This method breaks the primary platform target, Debian. See those PRs for previous discussion on this issue. Installations based on the Proxmox ISO are still outside of the scope of this role, but changes meant for them are okay as long as it doesn't break plain Debian installs.

[agross]

In this case what about removing it before taking other apt-related actions (for ISO installs, potentially with failed_when: false) and after the installation task (for plain Debian installs)?

Failed_when could be dynamically assigned if an ISO install can be detected (Ansible package facts? Would have to check.)

Given the number of PRs related to this your user base seems to include a bunch of people who use the ISO installer, myself included.

[agross]

What do you think about the idea of removing the repos before and after the installation?

• On Debian, before will be a no-op because they won't exist yet. After installation, the repo added by the installer will be removed.

• On ISO installs, the before task will remove the already present repo and allow the process to be completed without apt errors. After installation, removal will be a no-op.