steamPackages: fix attribute 'steamPackages' missing while cross eval

there's prior art for doing this

Artturin 4b9d0f34 9c7c0650

+1 -1
+1 -1
pkgs/games/steam/default.nix
··· 29 selfBuildHost = pkgsBuildHost.${steamPackagesAttr}; 30 selfBuildTarget = pkgsBuildTarget.${steamPackagesAttr}; 31 selfHostHost = pkgsHostHost.${steamPackagesAttr}; 32 - selfTargetTarget = pkgsTargetTarget.${steamPackagesAttr}; 33 }; 34 keep = self: { }; 35 extra = spliced0: { };
··· 29 selfBuildHost = pkgsBuildHost.${steamPackagesAttr}; 30 selfBuildTarget = pkgsBuildTarget.${steamPackagesAttr}; 31 selfHostHost = pkgsHostHost.${steamPackagesAttr}; 32 + selfTargetTarget = pkgsTargetTarget.${steamPackagesAttr} or {}; # might be missing; 33 }; 34 keep = self: { }; 35 extra = spliced0: { };