456 would do he job. You can run it with a variety of fork lengths that tranform the intended use/riding style. 100mm for a more XC focussed bike, or 150mm for a more hardcore hardtail type of thing. If you want the best of both worlds, a dual position fork would give you 2 different bikes geometry wise, but I guarentee as you get back into it you’d rarely drop the forks from their longest setting.
All the suggestions thus far are good though, Scandal, Soul, 456, Piglet/Pig would all do you well.
I would suggest that you go fo a secondhand bike first though, until you decide exactly what sort of riding floats your boat. No point spending a wad on new frame/parts as you’ll likely want a better/different bike a few months down the line.
I bought an XC bike when I got back into riding, and within a year had bought a much slacker hardcore hardtail, I then moved on to a 150mm full suss, but I still ride all 3 from time to time.