pdftoipe: move to homebrew/head-only

Closes Homebrew/homebrew#40528.

Signed-off-by: Dominyk Tiller <dominyktiller@gmail.com>

Library/Homebrew/tap_migrations.rb

@@ -155,6 +155,7 @@ TAP_MIGRATIONS = {
   "pdfjam" => "homebrew/tex",
   "pdf2image" => "homebrew/x11",
   "pdf2svg" => "homebrew/x11",
+  "pdftoipe" => "homebrew/head-only",
   "pebble-sdk" => "pebble/pebble-sdk",
   "pgplot" => "homebrew/x11",
   "pixie" => "homebrew/x11",