avahi: split headers to "dev" output

[trofi]

Description of changes

Things done

• Built on platform(s)
  • x86_64-linux
  • aarch64-linux
  • x86_64-darwin
  • aarch64-darwin
• For non-Linux: Is sandbox = true set in nix.conf? (See Nix manual)
• Tested, as applicable:
  • NixOS test(s) (look inside nixos/tests)
  • and/or package tests
  • or, for functions and "core" functionality, tests in lib/tests or pkgs/test
  • made sure NixOS tests are linked to the relevant packages
• Tested compilation of all packages that depend on this change using nix-shell -p nixpkgs-review --run "nixpkgs-review rev HEAD". Note: all changes have to be committed, also see nixpkgs-review usage
• Tested basic functionality of all binary files (usually in ./result/bin/)
• 23.05 Release Notes (or backporting 22.11 Release notes)
  • (Package updates) Added a release notes entry if the change is major or breaking
  • (Module updates) Added a release notes entry if the change is significant
  • (Module addition) Added a release notes entry if adding a new NixOS module
• Fits CONTRIBUTING.md.

[trofi]

avahi-compat fails to install headers in a wrong directory:

avahi-compat> ln: failed to create symbolic link '/nix/store/p71q03ibn5gccjhw4iqilis6ifvlfznj-avahi-compat-0.8/include/dns_sd.h': No such file or directory

Switching to draft.

[trofi]

Ended up being a symlink to $out in nix expression. Fixed. Ready for review.

[Artturin]

nix build ".#liblxi" ".#gvfs" ".#geoclue2" ".#hplip"