Remove use of jquery.tabIndex in jquery.wikiEditor.dialogs.js

This was used for setting incremental tabindex attributes
on the <button> elements of the "Find and replace" dialog
as opened from the "Advanced" toolbar section.

I was unable to find a difference in behaviour with and without
this code running.

Both with and without this, when tabbing from the first input
field in the dialog, the buttons are in the tab order after
the input fields (matching the visual rendering). Unclear
what this was doing.

Bug: T234581
Change-Id: I5de97733091d0e123913f272b00784205d69267f

extension.json

@@ -260,7 +260,6 @@
 				"jquery.cookie",
 				"jquery.throttle-debounce",
 				"jquery.suggestions",
-				"jquery.tabIndex",
 				"jquery.textSelection",
 				"jquery.ui.button",
 				"jquery.ui.dialog",

modules/jquery.wikiEditor.dialogs.js

@@ -122,9 +122,6 @@
 					.appendTo( $( 'body' ) )
 					.each( module.init )
 					.dialog( configuration );
-				// Set tabindexes on buttons added by .dialog()
-				dialogsModule.fn.setTabindexes( $dialogDiv.closest( '.ui-dialog' )
-					.find( 'button' ).not( '[tabindex]' ) );
 				if ( !( 'resizeme' in module ) || module.resizeme ) {
 					$dialogDiv
 						.on( 'dialogopen', dialogsModule.fn.resize )
@@ -180,19 +177,6 @@
 				$oldHidden.each( function () {
 					$( this ).attr( 'style', $( this ).data( 'oldstyle' ) );
 				} );
-			},
-
-			/**
-			 * Set the right tabindexes on elements in a dialog
-			 *
-			 * @param {Object} $elements Elements to set tabindexes on. If they already have tabindexes, this function can behave a bit weird
-			 */
-			setTabindexes: function ( $elements ) {
-				// Get the highest tab index
-				var tabIndex = $( document ).lastTabIndex() + 1;
-				$elements.each( function () {
-					$( this ).attr( 'tabindex', tabIndex++ );
-				} );
 			}
 		},