roboto-slab: use installFonts

pkgs/by-name/ro/roboto-slab/package.nix

@@ -1,10 +1,11 @@
 {
   lib,
-  stdenv,
+  stdenvNoCC,
   fetchFromGitHub,
+  installFonts,
 }:
 
-stdenv.mkDerivation {
+stdenvNoCC.mkDerivation {
   pname = "roboto-slab";
   version = "2.000";
 
@@ -15,14 +16,11 @@ stdenv.mkDerivation {
     sha256 = "1v6z0a2xgwgf9dyj62sriy8ckwpbwlxkki6gfax1f4h4livvzpdn";
   };
 
-  installPhase = ''
-    mkdir -p $out/share/fonts/truetype
-    cp -a fonts/static/*.ttf $out/share/fonts/truetype/
+  postPatch = ''
+    rm -r ./old
   '';
 
-  outputHashAlgo = "sha256";
-  outputHashMode = "recursive";
-  outputHash = "0g663npi5lkvwcqafd4cjrm90ph0nv1lig7d19xzfymnj47qpj8x";
+  nativeBuildInputs = [ installFonts ];
 
   meta = {
     homepage = "https://fonts.google.com/specimen/Roboto+Slab";