[Bug Report] Cannot decode obs['image'] because of no implementation of agent in minigrid/core/world_object.py

[EC2EZ4RD]

• Bug description
  Cannot decode obs['image'] because of no implementation of agent in minigrid/core/world_object.py

• Code

First, create an environment

import gymnasium as gym
from minigrid.wrappers import FullyObsWrapper
env = gym.make("MiniGrid-Empty-5x5-v0")
env = FullyObsWrapper(env)
obs, _ = env.reset()

Then, run

env.grid.decode(obs['image'])[0].render(env.tile_size, [0,0])

and return error:

File [~/miniconda3/envs/minigrid/lib/python3.10/site-packages/minigrid/core/world_object.py:101] in WorldObj.decode(type_idx, color_idx, state)
     99     v = Lava()
    100 else:
--> 101     assert False, "unknown object type in decode '%s'" % obj_type
    103 return v

• Solution
  Should add the render code of agent in minigrid/core/world_object.py

Checklist

• I have checked that there is no similar issue in the repo (required)