Warn when Box dtype is casted to lower precision (#1744)
Warn when Box dtype is casted to lower precision (#1744)

* Force explicit Box dtype

Having the `dtype` argument defaut to `np.float32` without warning can generate some unexpected issues.

For example:
```python
import gym
import numpy as np

num = np.array(3.1415926035897932)

gym.spaces.Box(-num, num).contains(num)  # returns False
```

* Warn on lowered precision

Farama-Foundation/Gymnasium,Farama-Foundation/Gymnasium