gearsystem: migrate to cask (Homebrew#52877)

Author: drhelius

Formula/gearsystem.rb

@@ -14,6 +14,7 @@
   "dwarf-fortress": "homebrew/cask",
   "geany": "homebrew/cask",
   "gearboy": "homebrew/cask",
+  "gearsystem": "homebrew/cask",
   "gimp": "homebrew/cask",
   "grads": "homebrew/cask",
   "gtkwave": "homebrew/cask",