Sadly its only Jet2 that seem to need drivers in the UK
Not quite the case, but even if it were, work is work and if it keeps the roof over your head and the type rating/experience current, what does it matter in the short term?
Very, very sad to see another great UK operator go under, but life goes on and I hope that everyone who used to work for Astraeus finds employment elsewhere.
Having been in a very similar situation in the distant and the recent past, my advice would be to do what you have to do then do what you'd really like to do when the opportunity arises.
What comes around goes around.