dlib: 19.9 -> 19.13 (#41953)

This fixes the latest `dlib` build for `nixpkgs` compliancy:

* Patched `setup.py` to use number of jobs defined in `$NIX_BUILD_CORES`
  rather than using all available cores.

* Bumped `dlib` to latest version (v19.13 ATM).

* Dropped `openblas` build input, `cblas` which actually works lives in
  `dlib/external`. Otherwise the test suite runs into segfaults (see
  https://github.com/NixOS/nixpkgs/pull/39255#issuecomment-384535129 for
  further reference).

* Added myself as maintainer in case of any further breakage in the
  future.

Closes #39255

/cc @dotlambda @ryantm

pkgs/development/libraries/dlib/default.nix

@@ -1,16 +1,16 @@
-{ stdenv, lib, fetchFromGitHub, cmake, pkgconfig, openblas, libpng, libjpeg
+{ stdenv, lib, fetchFromGitHub, cmake, pkgconfig, libpng, libjpeg
 , guiSupport ? false, libX11
 }:
 
 stdenv.mkDerivation rec {
-  version = "19.9";
+  version = "19.13";
   name = "dlib-${version}";
 
   src = fetchFromGitHub {
     owner = "davisking";
     repo = "dlib";
     rev ="v${version}";
-    sha256 = "0lc54r928j9dg7f2wn25m887z24d31wrc14v2hn6aknp1z084lrc";
+    sha256 = "11ia4pd2lm2s9hzwrdvimj3r2qcnvjdp3g4fry2j1a6z9f99zvz3";
   };
 
   postPatch = ''
@@ -19,14 +19,13 @@ stdenv.mkDerivation rec {
 
   enableParallelBuilding = true;
   nativeBuildInputs = [ cmake pkgconfig ];
-  buildInputs = [ openblas libpng libjpeg ] ++ lib.optional guiSupport libX11;
+  buildInputs = [ libpng libjpeg ] ++ lib.optional guiSupport libX11;
 
   meta = with stdenv.lib; {
     description = "A general purpose cross-platform C++ machine learning library";
     homepage = http://www.dlib.net;
     license = licenses.boost;
-    maintainers = with maintainers; [ christopherpoole ];
+    maintainers = with maintainers; [ christopherpoole ma27 ];
     platforms = platforms.linux;
   };
 }
-