nixos: use substitute rather than substituteAll in installer modules

[philiptaron]

Description of changes

Rationale is here:

• substituteAll is a terrible function and we need to stop using it / fix it respectively #237216

There's mostly no change to the files. I did make two bug fixes:

1. In nixos/modules/installer/tools/nixos-install.sh, there is no nix replacement variable, but there is a path substitution, so I added config.nix.package.out to the path.
2. In nixos/modules/installer/tools/nixos-enter.sh, there was no path replacement variable; I added it.

These changes validate the logic that motivated opening #237216. It's too easy to write a bug!

Previously:

• nixos-rebuild: use substitute rather than substituteAll #300308
• {nixos-container,lsb-release}: use substitute rather than substituteAll, fix cross-compilation #300322

Things done

• Built on platform(s)
  • x86_64-linux
  • aarch64-linux
  • x86_64-darwin
  • aarch64-darwin
• For non-Linux: Is sandboxing enabled in nix.conf? (See Nix manual)
  • sandbox = relaxed
  • sandbox = true
• 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/)
• 24.05 Release Notes (or backporting 23.05 and 23.11 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.