python3.pkgs.manticore: mark as broken only once

Fix ofborg's evaluation on the release-22.05 branch. It's hard to blame
anyone for causing this evaluation error. Both commits
43072cd017 and
c5b2704fcd created the `meta.broken`
attribute. The diff of both commits doesn't indicate either had the
other `broken` attribute written.

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

@@ -132,7 +132,5 @@ buildPythonPackage rec {
     license = licenses.agpl3Only;
     platforms = platforms.unix;
     maintainers = with maintainers; [ arturcygan ];
-    # m.c.manticore:WARNING: Manticore is only supported on Linux. Proceed at your own risk!
-    broken = stdenv.isDarwin;
   };
 }