Use new register method after gem bump of pronto to 0.11.3

Checkout: prontolabs/pronto#450

Author: Dakad

src/github_action_check_run_formatter.rb

@@ -123,15 +123,4 @@ def messages_by_runner
   end
 end
 
-begin
-  warn_level = $VERBOSE
-  $VERBOSE = nil
-  Pronto::Formatter.const_set(
-    :FORMATTERS,
-    Pronto::Formatter::FORMATTERS.merge(
-      'github_action_check_run' => Pronto::Formatter::GithubActionCheckRunFormatter
-    )
-  )
-ensure
-  $VERBOSE = warn_level
-end
+Pronto::Formatter.register(Pronto::Formatter::GithubActionCheckRunFormatter)