fix: remove duplicate require_relative in screenshot_matcher

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

Author: pftg

lib/capybara/screenshot/diff/screenshot_matcher.rb

@@ -6,8 +6,6 @@
 require_relative "browser_helpers"
 require_relative "vcs"
 require_relative "area_calculator"
-require_relative "screenshoter"
-require_relative "stable_screenshoter"
 
 module Capybara
   module Screenshot