Upgrade/Install: Fix broken sprintf() call when deleting a backup.

In `WP_Upgrader::delete_temp_backup()`, a malformed `sprintf()` call did not pass the value, triggering a Warning in PHP 7 and a Fatal Error in PHP 8.

This fixes the malformed `sprintf()` call by correctly passing the value.

Follow-up to [55720].

Props akihiroharai, afragen.
Merges [56550] to the 6.3 branch.
Fixes #59320.

git-svn-id: https://develop.svn.wordpress.org/branches/6.3@56582 602fd350-edb4-49c9-b593-d223f7449a82

src/wp-admin/includes/class-wp-upgrader.php

@@ -1206,8 +1206,7 @@ public function delete_temp_backup() {
  if ( ! $wp_filesystem->delete( $temp_backup_dir, true ) ) {
  $errors->add(
  'temp_backup_delete_failed',
- sprintf( $this->strings['temp_backup_delete_failed'] ),
- $args['slug']
+ sprintf( $this->strings['temp_backup_delete_failed'], $args['slug'] )
  );
  continue;
  }