gpscorrelate: enable on darwin

pkgs/applications/misc/gpscorrelate/default.nix

···
 
     license = licenses.gpl2Plus;
     homepage = "https://dfandrich.github.io/gpscorrelate/";
-    platforms = platforms.linux;
+    platforms = platforms.unix;
     maintainers = with maintainers; [ sikmir ];
   };
 }