Prevent line numbers from being voiced by screen readers
Prevent line numbers from being voiced by screen readers

Sets aria-hidden=true on .CodeMirror-gutter-wrapper elements

Fixes #6578

dperetti/CodeMirror,nightwing/CodeMirror,hackmdio/CodeMirror,nightwing/CodeMirror,nightwing/CodeMirror,dperetti/CodeMirror,hackmdio/CodeMirror,hackmdio/CodeMirror,wingify/CodeMirror,pabloferz/CodeMirror,pabloferz/CodeMirror,wingify/CodeMirror,dperetti/CodeMirror,pabloferz/CodeMirror,wingify/CodeMirror