Update Ansible version requirements

Tests were carried out like this:

- `virtualenv3 env`
- `./env/bin/pip install ansible==4.10.0 ansible-core==2.11.7`
- `./env/bin/ansible-playbook .....`

The lowest version of `ansible-core` available on PyPI right now is
2.11.0. That version has trouble with `ansible==4.0.0` though.
The errors we were hitting seemed to be resolved by others online by
using `ansible==4.10.0` instead, which has a minimum `ansible-core`
requirement of `2.11.7`, so that's what we went with.

Older versions of Ansible may work, but.. I'm having trouble
installing them and don't want to spend too much time on digging through
ancient versions and testing them out. People should just learn to run
up-to-date software.

docs/ansible.md

@@ -9,19 +9,14 @@ If your local computer cannot run Ansible, you can also run Ansible on some serv
 
 ## Supported Ansible versions
 
-Ansible 2.7.1 or newer is required ([last discussion about Ansible versions](https://github.com/spantaleev/matrix-docker-ansible-deploy/pull/743)).
+To manually check which version of Ansible you're on, run: `ansible --version`.
-
-Note: Ubuntu 20.04 ships with Ansible 2.9.6 which is a buggy version (see this [bug](https://bugs.launchpad.net/ubuntu/+source/ansible/+bug/1880359)), which can't be used in combination with a host running new systemd (more details in [#517](https://github.com/spantaleev/matrix-docker-ansible-deploy/issues/517), [#669](https://github.com/spantaleev/matrix-docker-ansible-deploy/issues/669)). If this problem affects you, you can: avoid running Ubuntu 20.04 on your host; run Ansible from another machine targeting your host; or try to upgrade to a newer Ansible version (see below).
-
-
-## Checking your Ansible version
 
-In most cases, you won't need to worry about the Ansible version.
+For the **best experience**, we recommend getting the **latest version of Ansible available**.
-The playbook will try to detect it and tell you if you're on an unsupported version.
 
-To manually check which version of Ansible you're on, run: `ansible --version`.
+We're not sure what's the minimum version of Ansible that can run this playbook successfully.
+The lowest version that we've confirmed (on 2022-11-26) to be working fine is: `ansible-core` (`2.11.7`) combined with `ansible` (`4.10.0`).
 
-If you're on an old version of Ansible, you should [upgrade Ansible to a newer version](#upgrading-ansible) or [use Ansible via Docker](#using-ansible-via-docker).
+If your distro ships with an Ansible version older than this, you may run into issues. Consider [Upgrading Ansible](#upgrading-ansible) or [using Ansible via Docker](#using-ansible-via-docker).
 
 
 ## Upgrading Ansible