ansible-scylla-node: ScyllaDB and OS compatibility check is outdated and inappropriately positioned.

[vreniers]

In the ansible-scylla-node role, there is a task related to upgrade namely main.yml which does a check whether or not the current OS is supported by the selected ScyllaDB version:

https://github.com/scylladb/scylla-ansible-roles/blob/master/ansible-scylla-node/tasks/upgrade/main.yml#L10

There are two issues:

• This support matrix is outdated, as it does not list e.g. Ubuntu 24, or very old Scylla OSS versions.
• Such a check should not be exclusively executed as part of an upgrade, but ideally anywhere.

This information needs to be updated per:

• https://opensource.docs.scylladb.com/stable/getting-started/os-support.html
• https://enterprise.docs.scylladb.com/stable/getting-started/os-support.html