python311Packages.pyhanko: Unmark broken on darwin (#355177)

pkgs/development/python-modules/pyhanko/default.nix

···
     changelog = "https://github.com/MatthiasValvekens/pyHanko/blob/v${version}/docs/changelog.rst";
     license = lib.licenses.mit;
     maintainers = [ ];
-    # Most tests fail with:
-    # OSError: One or more parameters passed to a function were not valid.
-    broken = stdenv.hostPlatform.isDarwin;
   };
 }