Add support for Melting Pot scenarios about shimmy HOT 6 OPEN

from shimmy import MeltingPotCompatibilityV0
import supersuit as ss
from meltingpot import scenario

mp_env = scenario.build_from_config(scenario.get_config('clean_up_0'))
env = MeltingPotCompatibilityV0(env=mp_env)
env = ss.observation_lambda_v0(env, lambda x, _: x["RGB"], lambda s: s["RGB"])
env = ss.frame_stack_v1(env, 4)
env = ss.pettingzoo_env_to_vec_env_v1(env)
env = ss.concat_vec_envs_v1(env, num_vec_envs=1, num_cpus=1, base_class="stable_baselines3")

Traceback (most recent call last):
  File "<stdin>", line 1, in <module>
  File "/usr/local/lib/python3.10/dist-packages/supersuit/vector/vector_constructors.py", line 64, in concat_vec_envs_v1
    vec_env = MakeCPUAsyncConstructor(num_cpus)(*vec_env_args(vec_env, num_vec_envs))
  File "/usr/local/lib/python3.10/dist-packages/supersuit/vector/concat_vec_env.py", line 23, in __init__
    self.vec_envs = vec_envs = [vec_env_fn() for vec_env_fn in vec_env_fns]
  File "/usr/local/lib/python3.10/dist-packages/supersuit/vector/concat_vec_env.py", line 23, in <listcomp>
    self.vec_envs = vec_envs = [vec_env_fn() for vec_env_fn in vec_env_fns]
  File "/usr/local/lib/python3.10/dist-packages/supersuit/vector/vector_constructors.py", line 12, in env_fn
    env_copy = cloudpickle.loads(cloudpickle.dumps(env))
  File "/usr/local/lib/python3.10/dist-packages/cloudpickle/cloudpickle_fast.py", line 73, in dumps
    cp.dump(obj)
  File "/usr/local/lib/python3.10/dist-packages/cloudpickle/cloudpickle_fast.py", line 632, in dump
    return Pickler.dump(self, obj)
TypeError: cannot pickle 'dmlab2d.dmlab2d_pybind.Lab2d' object