Fix CI failures: chromedriver path and Timecop Ruby 3.x private method

- Remove manual driver_path in github driver; Selenium Manager
  (selenium-webdriver >= 4.11) finds chromedriver automatically
- Drop setup-chrome from workflow; Chrome is pre-installed on ubuntu-latest
- Remove `private` from Timecop monkey patch in time_cop.rb — the patch
  accidentally made travel/unmock! private, causing NoMethodError on
  Ruby 3.x where explicit-receiver calls to private methods are forbidden

Co-Authored-By: Claude Sonnet 4.6 <noreply@anthropic.com>

Author: princejoseph

.github/workflows/ci.yml

@@ -34,13 +34,8 @@ jobs:
           working-directory: ruby/${{ matrix.gem }}
           bundler-cache: true
 
-      - name: Set up Chrome
-        uses: browser-actions/setup-chrome@v1
-        id: setup-chrome
-
       - name: Run specs
         run: bundle exec rake spec
         env:
           DRIVER: github
-          CHROMEWEBDRIVER: ${{ steps.setup-chrome.outputs.chromedriver-path }}
           RAILS_ENV: test

ruby/hyper-spec/lib/hyper-spec.rb

@@ -245,16 +245,13 @@ def self.on_server?
     Capybara::Selenium::Driver.new(app, browser: :chrome, options: options)
   end
 
-  # GitHub Actions: setup-chrome sets CHROMEWEBDRIVER to the chromedriver directory
+  # GitHub Actions: Selenium Manager (selenium-webdriver >= 4.11) finds chromedriver automatically
   Capybara.register_driver :chrome_headless_github_actions do |app|
     options = ::Selenium::WebDriver::Chrome::Options.new
     options.add_argument('--headless')
     options.add_argument('--no-sandbox')
     options.add_argument('--disable-dev-shm-usage')
     options.add_argument('--disable-gpu')
-    if (dir = ENV['CHROMEWEBDRIVER'])
-      Selenium::WebDriver::Chrome::Service.driver_path = File.join(dir, 'chromedriver')
-    end
     Capybara::Selenium::Driver.new(app, browser: :chrome, options: options)
   end
 

ruby/hyper-spec/lib/hyper-spec/internal/time_cop.rb

@@ -164,8 +164,6 @@ def run_pending_evaluations
 
   # Monkey patches to call our Lolex interface
   class Timecop
-    private
-
     def travel(mock_type, *args, &block)
       raise SafeModeException if Timecop.safe_mode? && !block_given?