python3Packages.aioh2: mark broken (#109409)

pkgs/development/python-modules/aioh2/default.nix

···
     description = "HTTP/2 implementation with hyper-h2 on Python 3 asyncio";
     license = licenses.bsd3;
     maintainers = [ maintainers.qyliss ];
+    broken = true; # requires h2<4
   };
 }