Fix DownloadError erroring itself

Library/Homebrew/cask/download.rb

@@ -81,6 +81,11 @@ module Cask
       super
     end
 
+    sig { override.returns(String) }
+    def download_name
+      cask.token
+    end
+
     private
 
     def quarantine(path)
@@ -94,11 +99,6 @@ module Cask
       end
     end
 
-    sig { override.returns(String) }
-    def download_name
-      cask.token
-    end
-
     sig { override.returns(T.nilable(::URL)) }
     def determine_url
       url

Library/Homebrew/downloadable.rb

@@ -109,13 +109,13 @@ class Downloadable
     EOS
   end
 
-  private
-
   sig { overridable.returns(String) }
   def download_name
     File.basename(determine_url.to_s)
   end
 
+  private
+
   sig { overridable.returns(T.nilable(URL)) }
   def determine_url
     @url