Use overlay for devshell

[whs-dot-hk]

Greetings @blaggacao

Context

Two days ago, a PR was merged on devshell side removing legacyPackages
https://github.com/numtide/devshell/pull/289/files#diff-206b9ce276ab5971a2489d75eb1b12999d4bf3843b7988cbe8d687cfde61dea0L13
lead to the follow error

error: attribute 'legacyPackages' missing

       at /nix/store/w36lpbbhyghaqdbzcnda35y27knsiblk-incl/lib/dev/mkShell.nix:58:5:

           57|   in
           58|     devshell.legacyPackages.mkShell {
             |     ^
           59|       imports = [configuration nixagoModule];

Solution

Today, pkgs overlays still support by devshell, so we can switch to use it to fix this issue

[blaggacao]

Thanks a lot for your help with maintenance! I really appreciate it.

[oneingan]

They revert this change: numtide/devshell#293