MAR-192: Switch to using NTP pools instead of servers:

- This is the recommended configuration by NTPsec, and also default on
Debian. Previuosly suggested values for servers have been pool
addresses in any case.

MAR-192: Switch to using NTPsec NTP server for increased security:

- This has for some time been a way better option, and it should also
provide for compatibility with Debian 12 Bookworm.

MAR-163: Attach noqa directives to task names (if skipping is applicable on task level) for better uniformity:

- This way the indentation of comment describing the directive can
always be on the same level everywhere (irrespective of how the rest
of task arguments are listed).

MAR-163: Reformat skip-QA directives for ANSIBLE0012 (Commands should not change things if nothing needs doing):

- Update codes used to identify the disabled QA checks.
- Switch to using new syntax that disables only a specific QA check
instead of all of them on a single task.
- Drop disabling QA checks on two command tasks, since they actually
use the "creates" directive (therefore passing the QA check).

MAR-148: Clean-up TODO entries for the common role coming from bugs in earlier versions of software:

- Switch to using the systemd task for reloads.
- Add back validation of pipreqcheck activation script file
permissions.
- Add back validation of missing ntp/ntpdate packages.

MAR-148: Fix Ansible warnings for the common role:

- Use the length filter for conditionals that require a (parameter)
list to be non-empty.
- Use explicit quoting for the cron task hour/minute.

MAR-127: Implemented time synchronisation set-up in common role:

- Added new parameter ntp_servers for defining list of servers to use.
- Deploy ntp and ntpdate packages and relevant configuration files.
- Updated tests, fixing expected restriction lines in ntp
configuration, and adding an additional test to make sure the ntp
daemon has reread its configuration.

MAR-114: Updated task syntax for the common role:

- Added quoting where it makes sense.
- Switched to using expanded syntax (instead of one-liners).
- Updated ordering of arguments in task definitions.

MAR-22: Linting fixes for test implementation for role 'common':

- Fixed small error in documentation for additional_groups parameter in the
'common' role.
- Do not perform Ansible lint checks on handlers that run commands.
- Fixed permission mode specification to include leading zero (i.e. mode=0640
instead of mode=640) when deploying directories, files, and templates.
- Do not perform Ansible lint checks for task managing update of CA certificate
cache (it must be done at that point).
- Use become_user in conjunction with become.
- Do not perform Ansible lint checks on command tasks that use the 'creates'
parameter.
- Do not use 'latest' version when installing pip in virtual environment used
for performing pip package upgrade checks.