Ansible 2.14.3 introduced a change that broke the method used for
restarting MariaDB and RabbitMQ serially [1][2]. In
I57425680a4cdbf0daeb9b2cc35920f1b933aa4a8 we limited to 2.14.2 to work
around this. Ansible upstream claim this behaviour was unintentional,
and will not fix it.

This change moves to a different approach where we use separate plays
with a 'serial' keyword to execute the restart.

This change also removes the restriction on the maximum supported
version of 2.14.2 on ansible-core - any 2.14 release is now supported.

[1] https://github.com/ansible/ansible/commit/65366f663de7d044f42ae6dd53368fd4c1f88b35
[2] https://github.com/ansible/ansible/issues/80848

Depends-On: https://review.opendev.org/c/openstack/kolla/+/884208

Change-Id: I5a12670d07077d24047aaff57ce8d33ccf7156ff