Previously, the `post_count` option value was not decremented when a post was deleted.
This change moves the `_update_posts_count_on_delete` action from `delete_post` hook to `after_delete_post` to ensure the deletion is taken into account.
Props henry.wright, pbearne, audrasjb.
Fixes#53443.
git-svn-id: https://develop.svn.wordpress.org/trunk@52207 602fd350-edb4-49c9-b593-d223f7449a82
