sunbeam log files limit of 10 is too small - [feature request supportability]

[Marcin Wilk]

The current limit of the sunbeam command log files is set to 10 [1]. That is too low especially since every execution of the sunbeam command generates a new file (even when only the '-h' or '--help' switches are provided). When reaching the limit the older files are deleted and it is very easy to lose logs from bootstrap/join/enable, etc command execution. That makes troubleshooting much harder on the data collected after some time from Customers' systems.

It would be helpful to increase the default limit and maybe not generate logs if the command is run with the 'help' switch.

[1] https://github.com/canonical/snap-openstack/blob/main/sunbeam-python/sunbeam/log.py#L23