figure out how to set swap size based on rpi-swap

[mstormi]

trixie Raspi OS now has rpi-swap pkg installed by default which is zram based swap.

The old dphys-swapfile based mechanism is no longer available. So we have to figure out how to set swapsize with this new setup and ensure it does not interfere with your zram setup.

[ecdye]

Fun stuff, I'll try and look at that next week sometime.