doctoc: remove dangling symlinks

Fixes https://github.com/NixOS/nixpkgs/issues/409046

+4
+4
pkgs/by-name/do/doctoc/package.nix
··· 18 19 npmDepsHash = "sha256-TbAnFpiN/v6xjQQznL/B180f0W48HPRqW21cO9XZhYA="; 20 21 dontNpmBuild = true; 22 23 passthru.tests = {
··· 18 19 npmDepsHash = "sha256-TbAnFpiN/v6xjQQznL/B180f0W48HPRqW21cO9XZhYA="; 20 21 + postInstall = '' 22 + find $out/lib/node_modules -xtype l -delete 23 + ''; 24 + 25 dontNpmBuild = true; 26 27 passthru.tests = {