Bug 1555240 - Remove unnecessary macOS scrollbar rule. r=bgrins

Differential Revision: https://phabricator.services.mozilla.com/D32954

--HG--
extra : moz-landing-system : lando

toolkit/themes/osx/global/nativescrollbars.css

@@ -76,12 +76,3 @@ scrollcorner {
   cursor: default;
   background-color: white;
 }
-
-/* ::::::::::::::::::::: MEDIA PRINT :::::::::::::::::::::: */
-@media print {
-  html|div scrollbar {
-    -moz-appearance: scrollbar;
-    -moz-binding: url("chrome://global/content/bindings/general.xml#empty");
-    cursor: default;
-  }
-}