[rb] Add deprecation annotation for headless (#11527)

* [rb] Add deprecation annotation to Chromium headless method
* [rb] Added the same changes for firefox

Author: TamsilAmani

rb/lib/selenium/webdriver/chromium/options.rb

@@ -168,6 +168,9 @@ def add_preference(name, value)
         #
 
         def headless!
+          WebDriver.logger.deprecate('`Options#headless!`',
+                                     "`options = Selenium::WebDriver::Options.chrome(args: ['--headless=chrome'])`",
+                                     id: :headless)
           add_argument '--headless'
         end
 

rb/lib/selenium/webdriver/firefox/options.rb

@@ -108,6 +108,9 @@ def add_preference(name, value)
         #
 
         def headless!
+          WebDriver.logger.deprecate('`Options#headless!`',
+                                     "`options = Selenium::WebDriver::Options.firefox(args: ['-headless'])`",
+                                     id: :headless)
           add_argument '-headless'
         end