ghostscript: apply patch to fix parallel build

The build process of ghostscript has missing dependencies, causing
failures in parallel builds (see hydra build
https://hydra.nixos.org/build/117095669/, reported as ghostscript bug
https://bugs.ghostscript.com/show_bug.cgi?id=702364 here)

pkgs/misc/ghostscript/default.nix

@@ -52,6 +52,9 @@ stdenv.mkDerivation rec {
       url = "https://git.ghostscript.com/?p=ghostpdl.git;a=patch;h=485904772c5f0aa1140032746e5a0abfc40f4cef";
       sha256 = "0z5gnvgpp0dlzgvpw9a1yan7qyycv3mf88l93fvb1kyay893rshp";
     })
+    # rebased version of upstream http://git.ghostscript.com/?p=ghostpdl.git;a=patch;h=1b4c3669a20c,
+    # Remove on update to version > 9.52
+    ./0001-Bug-702364-Fix-missing-echogs-dependencies.patch
   ];
 
   outputs = [ "out" "man" "doc" ];