Code Modernization: Fix a jQuery Migrate deprecation in wpdialog.

This changeset replaces a `focus()` shorthand in WP Core's customized jQuery UI widget `wpdialog` to avoid a jQuery Migrate deprecation notice in the browser's console.

Props TobiasBg, elifvish.
Fixes #56830.


git-svn-id: https://develop.svn.wordpress.org/trunk@55052 602fd350-edb4-49c9-b593-d223f7449a82

Author: audrasjb

src/js/_enqueues/lib/dialog.js

@@ -17,7 +17,7 @@
 			this._super();
 
 			// WebKit leaves focus in the TinyMCE editor unless we shift focus.
-			this.element.focus();
+			this.element._trigger('focus');
 			this._trigger('refresh');
 		}
 	});