Skip Redmine link comment when the URL is already in the PR body

If the PR title or body already contains the full bugs.ruby-lang.org
URL for a referenced ticket, there is no need to post a redundant link
in a comment.

Co-Authored-By: Claude Opus 4.6 (1M context) <noreply@anthropic.com>

Author: hsbt

tool/auto_review_pr.rb

@@ -133,6 +133,7 @@ def review_redmine_links(pr_number, pr, existing_comments)
     text = "#{pr[:title]}\n#{pr[:body]}"
 
     tickets = text.scan(REDMINE_TICKET_PATTERN).uniq
+    tickets.reject! { |_, number| text.include?("https://bugs.ruby-lang.org/issues/#{number}") }
     if tickets.empty?
       puts "Skipped: The PR ##{pr_number} doesn't reference any Redmine tickets."
       return