I installed it without -e option, but I got cannot import name 'constants' error.

I tried to install this repository as follows:

```
git clone https://github.com/deepmind/dm_control.git
cd dm_control/
pip3 install -r requirements.txt
```

But, after running the command, the following error occurred.

```
python3 ./dm_control/locomotion/soccer/explore.py
ImportError: cannot import name 'constants' from partially initialized module 'dm_control.mujoco.wrapper.mjbindings' (most likely due to a circular import) (/home/dl/DM_Control2/dm_control/dm_control/mujoco/wrapper/mjbindings/__init__.py)
```

Please let me know how to avoid it.

Start by reproducing the command from requirements.txt and running dm_control/locomotion/soccer/explore.py. Then inspect dm_control/mujoco/wrapper/mjbindings/__init__.py and the reported import path to determine why constants is unavailable; done means identifying a confirmed installation or import correction and documenting the verified result.

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