distrobox: refactor code

[chewblacka]

Description of changes

Refactor code:

• Use rec-less, overlay-style overridable recursive attributes (as per stdenv.mkDerivation: overlay style overridable recursive attributes #119942);
• Replace sha256 with hash

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.

[github-actions]

Backport failed for release-23.05, because it was unable to cherry-pick the commit(s).

Please cherry-pick the changes locally.

git fetch origin release-23.05
git worktree add -d .worktree/backport-255697-to-release-23.05 origin/release-23.05
cd .worktree/backport-255697-to-release-23.05
git checkout -b backport-255697-to-release-23.05
ancref=$(git merge-base 6a88110984d8bb2653ffe2abb57d18eabf3d7284 c0633919a68a239e71c9ffa281225c92f18e8060)
git cherry-pick -x $ancref..c0633919a68a239e71c9ffa281225c92f18e8060