Building docs on python 3.13 results in an import exception

[cibere]

Summary

Building the docs on 3.13 results in an import exception because imghdr has been removed in 3.13

Reproduction Steps

1. Create a fresh venv with python 3.13
2. Install the library's dependencies
3. Try to build the docs

Minimal Reproducible Code

py -3.13 -m venv venv
venv\scripts\activate
pip install .[docs]
cd docs
make html

Expected Results

The docs are successfully built and I can access them

Actual Results

Running Sphinx v4.4.0

Extension error:
Could not import extension sphinx.builders.epub3 (exception: No module named 'imghdr')

Intents

doesn't apply

System Information

• Python v3.13.1-final
• discord.py v2.5.0-alpha
  • discord.py metadata: v2.5.0a5129+g9806aeb8
• aiohttp v3.11.11
• system info: Windows 11 10.0.22631

Checklist

• I have searched the open issues for duplicates.
• I have shown the entire traceback, if possible.
• I have removed my token from display, if visible.

Additional Context

This came from a discord.py help thread

[mikeshardmind]

I've gone ahead and rescued imghdr similar to audioop here

similar state with it being a small, stable piece of the standard library that required no further changes and could have been left "as-is".

I'll open a PR with it as a docs-only, 3.13+ only dependency, but I'm not particularly attached. We'd need to upgrade to at least sphinx 6.6 to get to a version where sphinx does not depend on this.

[mikeshardmind]

#10053 being merged should have resolved this.