Robotex does not follow user-agent precedence rules

[MothOnMars]

Bug Steps:
Attempt to extract the delay for a user agent from a robots.txt file where the crawl-delay for a specific user agent appears after the rule for *. Example:
https://www.archives.gov/robots.txt

User-agent: *
Crawl-delay: 10
...
User-agent: usasearch
Crawl-delay: 2

Expected results:

> Robotex.new('usasearch').delay('https://www.archives.gov')
#=> 2

Actual results:

> Robotex.new('usasearch').delay('https://www.archives.gov')
#=> 10

See https://developers.google.com/search/reference/robots_txt#order-of-precedence-for-user-agents for precedence rules.