v2.9.0

What's Changed

• Update tooling to work with 2.9 by @rschmied in #35

Breaking change
With this release, the cfg.common.allowed_ipv4_subnets has been split into
two variables:

1. cfg.common.allowed_ipv4_subnets.mgmt which allows access to management
   ports tcp/22 (SSH) and tcp/9090 (Cockpit)
2. cfg.common.allowed_ipv4_subnets.cml2 which allows access to the CML2
   application on tcp/80, tcp/443 and tcp/1122. This gets also applied to
   the PATty port range, if PATty is enabled

The default for both is ["0.0.0.0/0"] (e.g. "any"). However, it is advisable
(and maybe even enforced by your policy) to restrict management access to a
specific subnet or a list of subnets.

• fix AWS 24.04 noble image name for the AWS mini variant (closes #32)
• fix certificate installation for 2.8 and newer in 03-letsencrypt.sh
• mandate CML TF provider 0.8.0 or newer
• make licensing a bit more robust (license.py)
• additional code to install Docker related dependencies (for 2.9)
• change stabilization timer code location to match 2.8 and newer in
  04-customize.sh
• updated config.yml to include newest reference platform node definitions
  and images. Some are commented -- need to adapt before deploying to match
  what is actually needed
• updated and reformatted documentation

Full Changelog: v2.8.0...v2.9.0