No difference - as you're in year 12 right now to get into a career in law youll have to take the SQE to qualify, which is an exam anyone from any degree discipline can take. From 2024 there's no advantage in having done a law degree like there is right now (if you graduated right now you'd have to do an extra year of studying if you took languages for degree).
I took Spanish and Frenh at A Level and now have a TC offer at a international law firm. I personally think my language skills were a huge factor in getting it, even though I am a law student right now. Less people can speak things like Spanish than you think so it can make you really stand out!