go-md2man: switch to buildGoModule

[zowoq]

Motivation for this change

Things done

• Tested using sandboxing (nix.useSandbox on NixOS, or option sandbox in nix.conf on non-NixOS linux)
• Built on platform(s)
  • NixOS
  • macOS
  • other Linux distributions
• Tested via one or more NixOS test(s) if existing and applicable for the change (look inside nixos/tests)
• Tested compilation of all pkgs that depend on this change using nix-shell -p nixpkgs-review --run "nixpkgs-review wip"
• Tested execution of all binary files (usually in ./result/bin/)
• Determined the impact on package closure size (by running nix path-info -S before and after)
• Ensured that relevant documentation is up to date
• Fits CONTRIBUTING.md.

[r-rmcgibbo]

Result of nixpkgs-review pr 118124 at 8eb8bbd run on aarch64-linux 1

16 packages marked as broken and skipped:

• linuxPackages-libre.oci-seccomp-bpf-hook
• linuxPackages.oci-seccomp-bpf-hook
• linuxPackages_5_10.oci-seccomp-bpf-hook
• linuxPackages_5_11.oci-seccomp-bpf-hook
• linuxPackages_5_4.oci-seccomp-bpf-hook
• linuxPackages_hardened.oci-seccomp-bpf-hook
• linuxPackages_latest-libre.oci-seccomp-bpf-hook
• linuxPackages_latest.oci-seccomp-bpf-hook
• linuxPackages_latest_hardened.oci-seccomp-bpf-hook
• linuxPackages_latest_xen_dom0.oci-seccomp-bpf-hook
• ...

1 package failed to build:

• dydisnix

29 packages built successfully:

• brillo
• buildah
• buildah-unwrapped
• charliecloud
• containerd
• cri-o
• crun
• disnix
• disnixos
• docker (docker-edge ,docker_20_10)
• docker-gc
• dysnomia
• go-md2man
• grype
• hercules-ci-agent
• k3s
• nix-prefetch-docker
• out-of-tree
• pipework
• podman
• podman-unwrapped
• python38Packages.jupyter-repo2docker
• python39Packages.jupyter-repo2docker
• runc
• skopeo
• teensy-loader-cli
• umoci
• vgrep
• zfs-prune-snapshots

Note that build failures may predate this PR, and could be nondeterministic or hardware dependent.
Please exercise your independent judgement.

---

Result of nixpkgs-review pr 118124 at 8eb8bbd run on x86_64-linux 1

2 packages marked as broken and skipped:

• linuxPackages-libre.oci-seccomp-bpf-hook
• linuxPackages_latest-libre.oci-seccomp-bpf-hook

1 package failed to build:

• dydisnix

1 package skipped due to time constraints:

• qmk_firmware

43 packages built successfully:

• brillo
• buildah
• buildah-unwrapped
• charliecloud
• containerd
• cri-o
• crun
• disnix
• disnixos
• docker (docker-edge ,docker_20_10)
• docker-gc
• dysnomia
• go-md2man
• grype
• hercules-ci-agent
• k3s
• linuxPackages.oci-seccomp-bpf-hook (linuxPackages_5_4.oci-seccomp-bpf-hook)
• linuxPackages_5_10.oci-seccomp-bpf-hook
• linuxPackages_5_11.oci-seccomp-bpf-hook (linuxPackages_latest.oci-seccomp-bpf-hook)
• linuxPackages_hardened.oci-seccomp-bpf-hook
• linuxPackages_latest_hardened.oci-seccomp-bpf-hook
• linuxPackages_latest_xen_dom0.oci-seccomp-bpf-hook
• linuxPackages_latest_xen_dom0_hardened.oci-seccomp-bpf-hook
• linuxPackages_lqx.oci-seccomp-bpf-hook
• linuxPackages_testing_bcachefs.oci-seccomp-bpf-hook
• linuxPackages_xen_dom0.oci-seccomp-bpf-hook
• linuxPackages_xen_dom0_hardened.oci-seccomp-bpf-hook
• linuxPackages_zen.oci-seccomp-bpf-hook
• nix-prefetch-docker
• nvidia-docker
• nvidia-podman
• out-of-tree
• pipework
• podman
• podman-unwrapped
• python38Packages.jupyter-repo2docker
• python39Packages.jupyter-repo2docker
• runc
• skopeo
• teensy-loader-cli
• umoci
• vgrep
• zfs-prune-snapshots

Note that build failures may predate this PR, and could be nondeterministic or hardware dependent.
Please exercise your independent judgement.