LC_Page_Admin.php でのローカルフックポイント実行処理での条件分岐が曖昧

何を想定して `doAction()` を2回コールしているか不明。

https://github.com/EC-CUBE/ec-cube2/blob/2df1730fadcdb003ce38bab8b58b29651e8bda7f/data/class/pages/admin/LC_Page_Admin.php#L179-L185

以下が正しい？
```php
// ローカルフックポイントを実行
$class_name = static::class;
if (str_ends_with($class_name, '_Ex')) {
$parent_class_name = get_parent_class($this);
$objPlugin->doAction($parent_class_name.'_action_before', [$this]);
} else {
$objPlugin->doAction($class_name.'_action_before', [$this]);
}
```

refs #1213

Read data/class/pages/admin/LC_Page_Admin.php around lines 179-185, then review the linked context in issue #1213. Determine why doAction() is called twice and how the _Ex class branch should behave; the work is done when the intended hook-point behavior is unambiguous and the conditional logic matches it.

Written by the indexing model from the issue text.