[wip] Case sensitive authors

[pcuenca]

Re: #3234.

[Wauplin]

Thanks! Did you use a script for it?

[pcuenca]

script

Yes, I told cursor about the /user/{username}/overview API, instructed it to look for 307s and fix those, and compile a list for 404s. I also told it to be careful with rate limits and gave it a disposable token - it knew how to read the headers but didn't do anything with them lol. It created this script:

check_authors.py

I verified all the 307s and then went through the 404s and found some replacements.

[pcuenca]

Fixed the 307s and some of the 404s I could find. As @Wauplin said, we can't completely avoid 404s unless we add redirects for each user rename, so I will merge this now.

There's an interesting remaining case, some posts use org names as authors, for example, this one uses huggingface, cc @mishig25 just for info.

[pcuenca]

This touches a few files, cc @mishig25 @julien-c in case you want to take a quick glance, otherwise I'll merge at the end of the day.

[julien-c]

lgtm, thanks!