Added a high contrast mode to screenshot cases.

[sarahboyce]

Branch description

To extend our accessibility tests, added screenshots in forced-colors mode.

Checklist

• This PR targets the main branch.
• The commit message is written in past tense, mentions the ticket number, and ends with a period.
• I have added or updated relevant tests.

[sarahboyce]

Screenshots can be seen in the Artifacts here: https://github.com/django/django/actions/runs/8701792464/
They are the ones with forced_colors in the file name

Here are a couple of examples:

This aims to aid the review process.
We may need to skip this on browsers that do not support forced-colors mode.

[knyghty]

Super cool 👍🏻

[ngnpope]

Hi @sarahboyce 👋🏻

Firstly, congratulations on your new role! 🥳 (Not crossed paths on any post or pull request recently, so sorry for being late to the party...)

This is great - it'll be helpful to have something for high contrast mode. This brings me to the point - you've named this forced_colors. It might be better to go for high_constrast instead, i.e. what we're generating rather than the mechanism by which it is achieved?

[sarahboyce]

Firstly, congratulations on your new role! 🥳

Thank you very much 😊

• Renamed to high_contrast
• This will still generate screenshots on other browsers but they will just be the same as the desktop (we only run screenshots for chrome in the CI)

[MHLut]

FYI, I have added some screenshots in #17910 per @sarahboyce's suggestion.

[sabderemane]

Look good to me, nice addition ❤️

[ngnpope]

Looks good. I have a little suggestion to skip the test on non-Chrome browsers which will work without affecting other screenshot cases as we're duplicating the test method.

Also need to update the PR title; perhaps:

Added a high contrast mode to screenshot cases.