maintainers/scripts/haskell/hydra-report: Add comments with error causes to broken list

[maralorn]

Description of changes

An example of a list of broken packages for broken.yaml generated by the script after this change looks like this:

❯ maintainers/scripts/haskell/hydra-report.hs mark-broken-list
  - type-natural # failure building library in job https://hydra.nixos.org/build/209356952 at 2023-02-19
  - haskell-language-server # dependency missing in job https://hydra.nixos.org/build/209951330 at 2023-02-19
  - json-rpc # test failure in job https://hydra.nixos.org/build/209953544 at 2023-02-19
  - ltext # test failure in job https://hydra.nixos.org/build/209953415 at 2023-02-19
  - exon # dependency missing in job https://hydra.nixos.org/build/209954193 at 2023-02-19
  - quickcheck-lockstep # dependency missing in job https://hydra.nixos.org/build/209953465 at 2023-02-19

I don’t know how long you people will be putting up with my feature creep to this script …

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.

[cdepillabout]

Code looks good, and this seems reasonable.

The only concern I'd have is that the reason something is broken may change over time. It is possible that having a link to broken build reports could be more confusing for users than helpful. Although that is just speculation, and I think it is worthwhile to try out the change in this PR and see if we like it.