treewide: Remove IFDs

[lorenzleutgeb]

Relates to:

• CI builds for darwin #24
• nix flake check with no-url-literals fails #39
• Repackage liberaforms without mach-nix #40

[jfly]

The kikit stuff LGTU (@ngi-nix/fungus)! Thanks for dealing with it. We actually had to remove IFD when we submitted this stuff to try to upstream it to nixpkgs in NixOS/nixpkgs#249464, sorry for the duplicated work!

[cleeyv]

This generally looks good to me! The only thing I see missing is to replace the use of liberaforms as an example in the README for adding and deploying a service: https://github.com/ngi-nix/ngipkgs/blob/main/README.md?plain=1#L43-L49

I think pretalx would be an excellent alternative to liberaforms in this section. It doesn't need to be exactly the same things covered, you can just copy what you've already put in your README for pretalx, so it could be changed to "Add and test a service" and we can include more about deployment later.

I'm working now on making this edit to the README using the pretalx example, hopefully a commit coming soon.

[mightyiam]

Nooice