Danger: don't require a review when 'database::approved' is set

Signed-off-by: Rémy Coutable <remy@rymai.me>

danger/database/Dangerfile

@@ -29,6 +29,8 @@ DB_FILES_MESSAGE = <<~MSG
 The following files require a review from the Database team:
 MSG
 
+DATABASE_APPROVED_LABEL = 'database::approved'
+
 non_geo_db_schema_updated = !git.modified_files.grep(%r{\Adb/schema\.rb}).empty?
 geo_db_schema_updated = !git.modified_files.grep(%r{\Aee/db/geo/schema\.rb}).empty?
 
@@ -46,6 +48,7 @@ if geo_migration_created && !geo_db_schema_updated
 end
 
 return unless gitlab_danger.ci?
+return if gitlab.mr_labels.include?(DATABASE_APPROVED_LABEL)
 
 db_paths_to_review = helper.changes_by_category[:database]