astropy: Knuth’s rule fails with simple and small array (eats up system's memory)

Description

The knuth_bin_width is not able to handle a small and simple array.

Expected behavior

A histogram should be generated, or an error shown explaining why it was not possible to obtain it.

Actual behavior

The function starts to gobble up the system’s memory.

Steps to Reproduce

import numpy as np
import matplotlib.pyplot as plt
from astropy.visualization import hist
arr = np.array([0.05555556, 0. , 0. , 0. , 0. ,1. , 0. , 0. , 0. , 0.5 ])
ax = plt.subplot(111)
hist(arr, bins='knuth', ax=ax)

System Details

Linux-5.5.0-050500-generic-x86_64-with-glibc2.10
>>> Python 3.8.8 (default, Feb 24 2021, 21:46:12) 
[GCC 7.3.0]
>>> Numpy 1.19.2
>>> astropy 4.2
>>> Scipy 1.5.2
>>> Matplotlib 3.3.1