refactor: [Authorizable Trait] move $matrix outside foreach loop

[christianberkman]

Description
$matrix = setting('AuthGroups.matrix'); can be moved out of the foreach ($permissions as $permission) loop since the value is the same for every iteration.

Checklist:

• Securely signed commits
• Component(s) with PHPDoc blocks, only if necessary or adds value
• Unit testing, with >80% coverage
• User guide updated
• Conforms to style guide

[datamweb]

LGTM!

[kenjis]

LGTM!