sorbet: Update RBI files.

Autogenerated by the [sorbet](https://github.com/Homebrew/brew/blob/master/.github/workflows/sorbet.yml) workflow.

Library/Homebrew/sorbet/rbi/hidden-definitions/hidden.rbi

@@ -5523,6 +5523,8 @@ class Cask::Cask
 
   def dictionary(&block); end
 
+  def discontinued?(&block); end
+
   def font(&block); end
 
   def homepage(&block); end
@@ -5715,6 +5717,8 @@ class Cask::DSL::Caveats
 
   def discontinued(*args); end
 
+  def discontinued?(); end
+
   def files_in_usr_local(*args); end
 
   def free_license(*args); end