as noted in #6276 (comment) and below, Halal quest should not be skipped on Vegan-only restaurants, because:

• just because it is Vegan-only, does not mean it is automatically Halal
• while Halal restaurants may be having meat, they may be vegan (including vegan-only) too, and that distinction is worth noting

In short, being Halal and being Vegan are orthogonal things, and it does not make sense to make one depend on the other.

(PR not tested yet, but seems simple enough)