remove aria-hidden made superfluous by removing interactive-table

frontend/app/components/wp-table/sort-header/sort-header.directive.html

@@ -1,4 +1,4 @@
-<div class="generic-table--sort-header-outer"  aria-hidden="true">
+<div class="generic-table--sort-header-outer">
   <span class="hierarchy-header--outer-span" ng-if="isHierarchyColumn">
     <accessible-by-keyboard execute="toggleHierarchy($event)"
                             ng-if="!isHierarchyDisabled"

frontend/app/components/wp-table/wp-table.directive.html

@@ -23,7 +23,7 @@
                           header-column="column">
           </th>
           <th class="wp-table--details-column -short hide-when-print">
-            <div class="generic-table--sort-header-outer" aria-hidden="true">
+            <div class="generic-table--sort-header-outer">
               <accessible-by-keyboard
                           execute="openColumnsModal()"
                           link-class="wp-table--columns-selection"