[Backport release-24.05] Fix nix flake show --all-systems from failing

[github-actions]

Bot-based backport to release-24.05, triggered by a label in #320639.

• Before merging, ensure that this backport is acceptable for the release.
  • Even as a non-commiter, if you find that it is not acceptable, leave a comment.

[grahamc]

(closing pending a double-check elsewhere...)

[grahamc]

Confirmed we're still getting the error this PR fixes.

[RossComputerGuy]

Confirmed we're still getting the error this PR fixes.

The same exact one? Would be strange that we still get the libressl or bootstrap errors.

[grahamc]

Yeah, the exact same bootstrap error:

evaluating 'checks.armv5tel-linux.nixosSystemAcceptsLib'...
      error:
             … while calling the 'head' builtin
               at /nix/store/i9syjxw0famqkabw2d01n723m3sc7vdn-source/lib/attrsets.nix:1575:11:
               1574|         || pred here (elemAt values 1) (head values) then
               1575|           head values
                   |           ^
               1576|         else

             … while evaluating the attribute 'value'
               at /nix/store/i9syjxw0famqkabw2d01n[72](https://github.com/DeterminateSystems/flakehub-mirror/actions/runs/9880125171/job/27287937454#step:7:74)3m3sc7vdn-source/lib/modules.nix:809:9:
                808|     in warnDeprecation opt //
                809|       { value = builtins.addErrorContext "while evaluating the option `${showOption loc}':" value;
                   |         ^
                810|         inherit (res.defsFinal') highestPrio;

             … while evaluating the option `system.build.toplevel':

             … while evaluating definitions from `/nix/store/i9syjxw0famqkabw2d01n723m3sc7vdn-source/nixos/modules/system/activation/top-level.nix':

             (stack trace truncated; use '--show-trace' to show the full, detailed trace)

             error: missing bootstrap url for platform armv5te-unknown-linux-gnueabi

...which I think makes sense, because the PR which fixed it in master never was backported to stable. Right?

[grahamc]

At any rate, this PR fixes the issue, and nix flake show --all-systems works again.

[RossComputerGuy]

At any rate, this PR fixes the issue, and nix flake show --all-systems works again.

Gotcha, I understand now. I thought you were mentioning that this PR didn't work in 24.05.

[cole-h]

Ignoring the failed formatting check because the files that are failing as "not formatted" were not touched here.