Bump selenium-webdriver from 4.0.0 to 4.11.0

Webdrivers doesn't seem to be working with GitHub Actions since Chrome
changed the way to download ChromeDriver [1].

Luckily, webdrivers functionality has recently been added directly to
selenium-webdriver, and version 4.11.0 is compatible with the new way to
download ChromeDriver.

So we're updating selenium-webdriver and removing webdrivers.

Note we now have to use the `Options` class instead of the
`Capabilities`. We're updating Capybara since its changelog mentions its
latest version also adapts these changes in Selenium.

[1] https://groups.google.com/g/chromedriver-users/c/qVPTFXnedw0

spec/rails_helper.rb

@@ -54,17 +54,14 @@ end
 FactoryBot.use_parent_strategy = false
 
 Capybara.register_driver :headless_chrome do |app|
-  capabilities = Selenium::WebDriver::Remote::Capabilities.chrome(
-    "goog:chromeOptions" => {
-      args: %W[headless no-sandbox window-size=1200,800 proxy-server=#{Capybara.app_host}:#{Capybara::Webmock.port_number}]
-    }
-  )
+  options = Selenium::WebDriver::Chrome::Options.new.tap do |opts|
+    opts.add_argument "--headless"
+    opts.add_argument "--no-sandbox"
+    opts.add_argument "--window-size=1200,800"
+    opts.add_argument "--proxy-server=#{Capybara.app_host}:#{Capybara::Webmock.port_number}"
+  end
 
-  Capybara::Selenium::Driver.new(
-    app,
-    browser: :chrome,
-    capabilities: capabilities
-  )
+  Capybara::Selenium::Driver.new(app, browser: :chrome, options: options)
 end
 
 Capybara.exact = true