Add ansible.posix collection as a requirement, latest release.

[oscarcarlsson]

Otherwise roles/custom/matrix-synapse/tasks/import_media_store.yml won't run, taking the entire playbook with it.

[spantaleev]

I wonder if we should be installing these collections ourselves or let the user's Ansible distribution do it. On Archlinux, the ansible package installs some 50+ collections already, so nothing else is necessary. On Alpinelinux (which handles our devture/ansible container, see docs/ansible.md for running Ansible in a container), it's the same - all these collections are included as part of the Ansible 6.5.0 distribution.

Us installing collections manually means we're overriding whatever is installed by the user on their system. We'd then need to maintain these collections (it's not just ansible.posix, I think) up to date. I don't know if these collections work on all versions of Ansible we support or if some releases work on newer versions only.

On the plus side, we'll know that all dependencies are installed and pinned to versions we know to work.

[etkecc]

ansible-core and ansible are completely different things nowadays. The core package contains ansible "engine" and builtin modules/plugins only, the ansible package contains collections and whatnot.

Playbook's requirement is ansible, not just ansible-core.
@spantaleev due to confusing naming of ansible packages, could you update the prerequisites to explicitly state that playbook requires both (ansible and ansible-core), please? That part, specifically:

The Ansible program being installed on your own computer

of the https://github.com/spantaleev/matrix-docker-ansible-deploy/blob/master/docs/prerequisites.md#prerequisites section