docker-machine{,-kvm,-xhyve}: remove

[katexochen]

Description of changes

docker-machine has been deprecated and archived in 2021, see
https://github.com/docker/machine
docker/roadmap#245

Not sure how useful docker-machine drivers are without docker machine.
Removing the following two, as they haven't been touched for years in-tree as upstream:

docker-machine-kvm, last update 7 years ago:
https://github.com/dhiltgen/docker-machine-kvm

docker-machine-driver-xhyve, last update 5 years ago:
https://github.com/machine-drivers/docker-machine-driver-xhyve

There are still docker-machine-hyperkit and docker-machine-kvm2, these use a forked version of docker-machine, so they can be considered somehow maintained. (But I wouldn't be sad to remove them, too, if not needed).

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.

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