Move coremod to the boneyard, replaced by libxmp-lite

Closes Homebrew/homebrew#37055.

Signed-off-by: Jack Nagel <jacknagel@gmail.com>

Library/Homebrew/tap_migrations.rb

@@ -24,6 +24,7 @@ TAP_MIGRATIONS = {
   "cmucl" => "homebrew/binary",
   "comparepdf" => "homebrew/boneyard",
   "connect" => "homebrew/boneyard",
+  "coremod" => "homebrew/boneyard",
   "curlftpfs" => "homebrew/x11",
   "cwm" => "homebrew/x11",
   "dart" => "dart-lang/dart",