Remove requests code

[omkar-334]

What does this PR do?

Removes requests code from setup, src and utils files.
Fixes #42817 partially

• Quality checks: make fixup passes with no errors

cc @CoderTCY @Wauplin @Rocketknight1

notes -

1. I've removed requests from setup/workflow files as well, you might want to check the first commit.
2. A few formatting fixes like "spacing around operators" got added in as well

[github-actions]

[For maintainers] Suggested jobs to run (before merge)

run-slow: align, beit, bit, blip, blip_2, chameleon, clipseg, conditional_detr, convnext, convnextv2, d_fine, deformable_detr, deit, depth_anything, detr, dinov2

[guibruand]

Hello, I got some issues with the current port to httpx.
I managed to set up huggingface_hub calls using the set_factory_client() with my custom httpx Client, and it would be nice if all httpx sessions in transformers rely on the same mechanism.

One way to do it would be for example:

from huggingface_hub import get_session

client = get_session()
result = client.post(....)

This also concerns some other portions of code (like safetensors_conversion.py).
Thank you for your support.