ocaml ≤ 4.05: mark as broken on Aarch64

[vbgl]

Motivation for this change

#46726 marked all versions of OCaml as broken on Aarch64, which is a bit too much. I hope this one is better.

cc/ @Mic92.

Things done

• Tested using sandboxing (nix.useSandbox on NixOS, or option sandbox in nix.conf on non-NixOS)
• 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 nox --run "nox-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)
• Fits CONTRIBUTING.md.

---

[vbgl]

@GrahamcOfBorg build ocaml

[GrahamcOfBorg]

Success on x86_64-darwin (full log)

Attempted: ocaml

Partial log (click to expand)

/nix/store/99sracn8p06w9lqpnx7aqysq268k5wmg-ocaml-4.06.1

[GrahamcOfBorg]

Success on x86_64-linux (full log)

Attempted: ocaml

Partial log (click to expand)

/nix/store/plhkx3w0n3ad6kn40936ic73k6wx28fm-ocaml-4.06.1

[GrahamcOfBorg]

Success on aarch64-linux (full log)

Attempted: ocaml

Partial log (click to expand)

these paths will be fetched (57.47 MiB download, 262.50 MiB unpacked):
  /nix/store/qzsja41zxyp12x4w03djq3k3rhq8qzww-ocaml-4.06.1
  /nix/store/rv8fv2kafxwmyas8f7y30pnklf2ljg5r-x11env
copying path '/nix/store/rv8fv2kafxwmyas8f7y30pnklf2ljg5r-x11env' from 'https://cache.nixos.org'...
copying path '/nix/store/qzsja41zxyp12x4w03djq3k3rhq8qzww-ocaml-4.06.1' from 'https://cache.nixos.org'...
/nix/store/qzsja41zxyp12x4w03djq3k3rhq8qzww-ocaml-4.06.1

[Mic92]

Please also backport to 18.09.

[xeji]

backported to 18.09: 355a037