Fixes #30932: Rescue from RecordInvalid for plugin role creation (#8032)

The exception can be raised two if Rails environments start in parallel (two requests, one request and a rake task) and permissions are not yet populated. Then the race condition can occur, as two different requests are trying to create the same role. This is another exception that was observed during this race condition, so we need to rescue from it too.

Fixes #28767: Drop extra transaction from plugin Role creation

Fixes #27380 - Handle non-unique role on creation (#6939)

Fixes #19983 - allow setting role description

Fixes #19787 - Fix Layout/SpaceAfterComma cop

Fixes #23081 - Fix Style/SafeNavigation cop

Fixes #19039 - Lock plugin roles

fixes #19317, #10927 - move registries to autoload_once path

Partially reverts 70ce8fe to reinstate autoload_once_paths as the
preferred way to load registry-type objects with class variables
containing data set up during app initialisation (e.g. plugin
registrations, menu items.)...

Refs #18001 - Avoid role extending from rake tasks permission

Fixes #18001 - Add plugin permissions to core's roles