Fix instances of RuboCop violations

What does this MR do and why?

To be able to turn on RuboCop checks in pipelines, we want to clean up existing violations.

This MR resolves:

• Layout/EmptyLineAfterMagicComment (https://docs.rubocop.org/rubocop/cops_layout.html#layoutemptylineaftermagiccomment)
• Lint/UnusedMethodArgument (https://docs.rubocop.org/rubocop/cops_lint.html#lintunusedmethodargument)

For the whole project.

Screenshots, screen recordings, or links to review app

• Alert boxes (admonitions):
  • https://eread-fix-white-space-and-unused-method-argument-rubocop-violat.docs.gitlab-review.app/ee/development/documentation/styleguide/#alert-boxes
  • https://eread-fix-white-space-and-unused-method-argument-rubocop-violat.docs.gitlab-review.app/ee/development/documentation/feature_flags.html#use-a-note-to-describe-the-state-of-the-feature-flag
• Product tier badge examples:
  • https://eread-fix-white-space-and-unused-method-argument-rubocop-violat.docs.gitlab-review.app/ee/administration/
  • https://eread-fix-white-space-and-unused-method-argument-rubocop-violat.docs.gitlab-review.app/ee/administration/file_hooks.html
  • https://eread-fix-white-space-and-unused-method-argument-rubocop-violat.docs.gitlab-review.app/ee/user/group/manage.html#restore-a-group
• Mermaid:
  • https://eread-fix-white-space-and-unused-method-argument-rubocop-violat.docs.gitlab-review.app/ee/user/markdown.html#mermaid
  • https://eread-fix-white-space-and-unused-method-argument-rubocop-violat.docs.gitlab-review.app/ee/ci/pipelines/pipeline_architectures.html#basic-pipelines
• Icons:
  • https://eread-fix-white-space-and-unused-method-argument-rubocop-violat.docs.gitlab-review.app/ee/user/admin_area/#admin-area-sections
  • https://eread-fix-white-space-and-unused-method-argument-rubocop-violat.docs.gitlab-review.app/ee/development/documentation/styleguide/#gitlab-svg-icons
• Introduced in blocks:
  • https://eread-fix-white-space-and-unused-method-argument-rubocop-violat.docs.gitlab-review.app/ee/user/project/members/#add-groups-to-a-project
  • https://eread-fix-white-space-and-unused-method-argument-rubocop-violat.docs.gitlab-review.app/ee/user/enterprise_user/#disable-two-factor-authentication
• Tabs:
  • https://eread-fix-white-space-and-unused-method-argument-rubocop-violat.docs.gitlab-review.app/ee/development/documentation/styleguide/#tabs
  • https://eread-fix-white-space-and-unused-method-argument-rubocop-violat.docs.gitlab-review.app/ee/administration/application_settings_cache.html

How to set up and validate locally

Numbered steps to set up and validate the change are strongly suggested.

1. Configure a local GitLab Docs environment: https://gitlab.com/gitlab-org/gitlab-docs/-/blob/main/doc/setup.md.

Merge request acceptance checklist

This checklist encourages us to confirm any changes have been analyzed to reduce risks in quality, performance, reliability, security, and maintainability.

• I have evaluated the MR acceptance checklist for this merge request.