docker.nix: Prevent double copy of nixpkgs source tree (backport #13326)#13620

mergify[bot] merged 1 commit into2.29-maintenanceNixOS/nix:2.29-maintenancefrom

mergify/bp/2.29-maintenance/pr-13326NixOS/nix:mergify/bp/2.29-maintenance/pr-13326Copy head branch name to clipboard