[BUG] AutoReset not enabled for MuJoCo envs

[dtch1997]

Required prerequisites

• I have read the documentation https://omnisafe.readthedocs.io.
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What version of OmniSafe are you using?

0.5.1.dev11+g7432fc2

System information

3.10.12 (main, Jul 5 2023, 18:54:27) [GCC 11.2.0] linux
0.5.1.dev11+g7432fc2

Problem description

AutoReset not enabled for MuJoCo envs resulting in crash when learning agent.

Reproducible example code

The Python snippets:

Command lines:

python examples/train_policy --env-id Hopper-v4

Extra dependencies:

Steps to reproduce:

Traceback

Traceback (most recent call last):
  File "/home/daniel/Documents/github/rl_cbf/rl_cbf/safe_rl/train_policy.py", line 91, in <module>
    agent.learn()
  File "/home/daniel/Documents/github/rl_cbf/.venv/lib/python3.10/site-packages/omnisafe/algorithms/algo_wrapper.py", line 172, in learn
    ep_ret, ep_cost, ep_len = self.agent.learn()
  File "/home/daniel/Documents/github/rl_cbf/.venv/lib/python3.10/site-packages/omnisafe/algorithms/on_policy/base/policy_gradient.py", line 246, in learn
    self._env.rollout(
  File "/home/daniel/Documents/github/rl_cbf/.venv/lib/python3.10/site-packages/omnisafe/adapter/onpolicy_adapter.py", line 118, in rollout
    info['final_observation'][idx],
KeyError: 'final_observation'

Expected behavior

Training works with MuJoCo envs.

Additional context

No response

[Gaiejj]

After careful reviewing of omnisafe/envs/mujoco_env.py file, I approve with your opinion and I think setting need_auto_reset_wrapper = True is critical to solve that problem. Thanks to your pull request in #269.