Bump to RabbitMQ 4.1.x

Boot steps: depend on pre_flight, do not enable anything

There are no boot steps that might depend on the one
defined by this plugin.

References rabbitmq/rabbitmq-server#13394.

Closes #298

Merge pull request #292 from cloudamqp/4_0

Ensure Mnesia is running when Khepri is used as main metadata store

rabbitmq-delayed-message-exchange v3.13.0

version 3.12.0

Target 3.11.x on this branch

Merge pull request #197 from cloudamqp/publish_out_stats

Bump exchange publish out metric when routing delayed messages

Merge pull request #195 from rabbitmq/rabbitmq-delayed-message-exchan…

…ge-194

List 3.10 as supported, drop 3.8 (which is out of support)

(cherry picked from commit 655f3a7)

List 3.9.x as a supported version, drop 3.7.x

since 3.7 has been out of support for a while.

Closes #172

Merge pull request #163 from mwfriedm/master

Use the rabbit_table facility to defer timeout to configuration value

(cherry picked from commit bdbd22c)