Warning
This may potentially violate BlueSky's ToS, or even local laws. As such it's probably best that you just don't use BlueSky for DMs until someone invents a time machine. If you decide to use this anyway, I'm certainly not responsible. I just did this for the funsies!
This ViolentMonkey user script intercepts the fetch request to https://bsky.app/ipcc which, if you're in the UK, has a response like this:
{"countryCode":"GB","isAgeRestrictedGeo":true}
All we actually need to do is set isAgeRestrictedGeo
to false, but you might as well move countries while you're at it.