Remove magic comments from Ruby files (!5456)

CHANGELOG

app/helpers/commits_helper.rb

app/uploaders/artifact_uploader.rb

app/uploaders/attachment_uploader.rb

app/uploaders/avatar_uploader.rb

app/uploaders/file_uploader.rb

app/uploaders/lfs_object_uploader.rb

spec/lib/banzai/filter/relative_link_filter_spec.rb

spec/lib/banzai/filter/table_of_contents_filter_spec.rb

spec/lib/banzai/filter/upload_link_filter_spec.rb