dev-cmd/typecheck: Disallow --fix when in taps too

- This could autocorrect files in Homebrew/brew when
  we should be targetting the tap, because of the
  weird hierarchy thing
  (https://github.com/Homebrew/brew/pull/18027#issuecomment-2294896044).

Co-authored-by: Bo Anderson <mail@boanderson.me>

Library/Homebrew/dev-cmd/typecheck.rb

@@ -46,6 +46,8 @@ module Homebrew
       def run
         if (args.dir.present? || args.file.present?) && args.named.present?
           raise UsageError, "Cannot use `--dir` or `--file` when specifying a tap."
+        elsif args.fix? && args.named.present?
+          raise UsageError, "Cannot use `--fix` when specifying a tap."
         end
 
         update = args.update? || args.update_all?