Bug summary

Hello,

It is the second time in 2.5 years that a Matplotlib release breaks all our doctests because plt.gca() returns a different type. It also happened around July 2020: colour-science/colour@d5f6800

There is no notice in the release notes and it is kind of wrecking havoc on our end. I will be using longer ellipsis from now on but I was wondering if you guys had considered using SemVER?

Code for reproduction

N/A

Actual outcome

Colour's doctests are sad! :(

Expected outcome

Happy doctests!

Additional information

No response

Operating system

No response

Matplotlib Version

3.7

Matplotlib Backend

No response

Python version

No response

Jupyter version

No response

Installation

None