2022-July-12 - 2.6+4121b33

Infra: run_ansible script improvements (#10868)

- Fix mismatch of '--env' variable printed in doc and expected in switch statement.
To fix this mismatch, we add '-env' as an additional option, and update the documentation
to give what seems to be a more consistent double dash prefix.

- Fix ansible_config environment variable, 'ANSIBLE_CFG' was just the wrong env
variable name.

- Remove post-deployment cleanup. We now run 'autoremove' as part of the common
apt packages installation, we no longer need to run an ad-hoc command for this.