Description of changes

1. dt-schema is an application, so it can pin jsonschema to 4.17
2. mark python3.pkgs.dtschema broken with jsonschema > 4.17
3. mark python3.pkgs.dtschema broken on Darwin

Some context about each of these points:

1. Per discussion in Raising the jsonschema cap to allow 4.18.* devicetree-org/dt-schema#108, dt-schema will need more time before it can support jsonschema 4.18.
2. The package even on master is broken on Darwin right now.

This is currently broken on staging-next (#245935).

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/)
• 23.11 Release Notes (or backporting 23.05 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.