Remove unused utility

Author: thibaudcolas

examples/utils/_utilities.scss

@@ -63,13 +63,3 @@
 .custom-toolbar-plugins {
   margin: 2rem 1rem 0 8rem;
 }
-
-// See https://snook.ca/archives/html_and_css/hiding-content-for-accessibility.
-.u-visually-hidden {
-  // stylelint-disable-next-line declaration-no-important
-  position: absolute !important;
-  height: 1px;
-  width: 1px;
-  overflow: hidden;
-  clip: rect(1px, 1px, 1px, 1px);
-}