You are trying to add Flightaware repository to Bookworm.
As Flightaware has not yet released piaware packages for Bookworm, there is no Release file, and hence you get error messages.
Better use Bullseye image, for which packages and Release file are available in Flightaware repository.
If you are keen to use Bookworm image, then
EITHER
Wait till Flightaware releases their packages for Bookworm
OR
Build these packages yourself from source-code. I have done this using automated install script, so it is easy, but time consuming.
https://discussions.flightaware.com/t/piaware-for-rpi-os-bookworm/90229/17