potrace: 1.15 -> 1.16 (#69748)

* potrace: 1.15 -> 1.16

Semi-automatic update generated by
https://github.com/ryantm/nixpkgs-update tools. This update was made
based on information from
https://repology.org/metapackage/potrace/versions

* potrace: enable tests

Upstream provides a test suite with make check

pkgs/applications/graphics/potrace/default.nix

···
 
 stdenv.mkDerivation rec {
   pname = "potrace";
-  version = "1.15";
+  version = "1.16";
 
   src = fetchurl {
     url = "http://potrace.sourceforge.net/download/${version}/potrace-${version}.tar.gz";
-    sha256 = "17ajildjp14shsy339xarh1lw1p0k60la08ahl638a73mh23kcx9";
+    sha256 = "1k3sxgjqq0jnpk9xxys05q32sl5hbf1lbk1gmfxcrmpdgnhli0my";
   };
 
   configureFlags = [ "--with-libpotrace" ];
 
   buildInputs = [ zlib ];
+
+  enableParallelBuilding = true;
+  doCheck = true;
 
   meta = with stdenv.lib; {
     homepage = http://potrace.sourceforge.net/;