This is the setup i got working in this thread: ada-mode 8.1.0, installed via package-install in Emacs 29.3, ./build.sh using alr 2.0 to build all dependencies, including GNAT.
$ alr toolchain
CRATE VERSION STATUS NOTES
gprbuild 22.0.1 Default
gnat_native 13.2.1 Default
i’ll try to check out the AppImages when i can.