Remove taming_transformers dependency

[akx]

Description

I noticed that the taming_transformers repository takes 2.5 minutes to clone (history and all 😩) and is hueg liek xbox pretty big on disk:

$ du -hs repositories/taming-transformers/
566M	repositories/taming-transformers/

and we only ever used a single class from a single module therein, so why not just yeet the whole thing and vendor in that single module?

Of course there might be something I don't know, but this seems pretty straightforward...

Checklist:

• I have read contributing wiki page
• I have performed a self-review of my own code
• My code follows the style guidelines
• My code passes tests

[AUTOMATIC1111]

that's a bold move

[akx]

that's a bold move

let's see if it pays off