Update Ruby dependencies

This MR contains the following updates:

Package	Update	Change
gitlab-styles	minor	~> 5.1.0 -> ~> 5.4.0
lefthook	patch	~> 0.7 -> ~> 0.7.0
yard	patch	~> 0.9 -> ~> 0.9.0

MR created with the help of gitlab-org/frontend/renovate-gitlab-bot

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