Updated $_old_files to remove SimplePie Core.php

Author: shazzad

src/wp-admin/includes/update-core.php

@@ -847,6 +847,7 @@
 	'wp-includes/blocks/post-author/editor-rtl.css',
 	'wp-includes/blocks/post-author/editor-rtl.min.css',
 	'wp-includes/SimplePie/src/Decode',
+	'wp-includes/SimplePie/src/Core.php'
 );
 
 /**