Drop `@package` tag in *.php

Drop `@package` tag in *.php

This does not provide a real value-add, because it is effectively redundant
with the namespace and is easily forgotten to adjust when copying the comment
from somewhere as a blueprint.

Changes performed using:

    find wcfsetup/ -iname '*.php' -print0 |xargs -0 sed -i '/\* @package.*WoltLabSuite/d'