Update rubocop requirement to ~> 0.58.1

Updates the requirements on [rubocop](https://github.com/rubocop-hq/rubocop) to permit the latest version.
- [Release notes](https://github.com/rubocop-hq/rubocop/releases)
- [Changelog](https://github.com/rubocop-hq/rubocop/blob/master/CHANGELOG.md)
- [Commits](https://github.com/rubocop-hq/rubocop/commits/v0.58.1)

Signed-off-by: dependabot[bot] <support@dependabot.com>

Author: dependabot-support

Gemfile

@@ -59,5 +59,5 @@ gem "uswds-jekyll" # 18F/federalist-docs
 gem "jekyll_pages_api_search", group: :jekyll_plugins # 18F/federalist-docs
 
 group :dev do
-  gem "rubocop", "~> 0.57.0"
+  gem "rubocop", "~> 0.58.1"
 end