You can’t obviously, but you still can jailbreak ios 9, install any cydia tweaks including desktop, console and emulator apps, as well as downgrade it to ios 6, if more working cydia apps are needed.
Of course the are in half dead state, but you still can do whatever you want with iOS (if you know how).
You may want to look into things like: https://projectsandcastle.org/status. Like the other commenter said, iOS is locked down and I don't think Sandcastle supports iPad (it looks dead now). If you want a Linux tablet, look at the JingPad, or just any old Android tablet.
There is a chance you could go through _lots_ of work to get some _Android_ device to work on raw Linux with the edk2-sdm845 UEFI firmware (https://github.com/edk2-porting/edk2-sdm845) that chainloads from the Android bootloader (ABL).
Blink[1] is a really cool open source app that will give you a shell on iOS and allow you to SSH into another machine. You can install it yourself, or purchase from the App Store.
If you want to use another computer you own, rather than a server in the cloud, Tailscale[2] will let you easily connect when away from home.
