chore: switch tags

[chonk-lain]

as per my communications with the HF people (internally) i think the best course of action will be to switch the tags to something else than birefnet as that will contradict with some of the internal workings (code snippet support, download count, ... )
which already shows, by the time i'm making this pr the HF repo shows the following erroneous code snippet

this will be an essential fix, and in the upcoming near future when our code snippet officially deploys on the hub there will be no friction with all of these inner workings.

TLDR;
switch tags from birefnet-> biref

[Copilot]

Pull request overview

This PR updates the Hugging Face Hub tag used to identify the BiRefNet model (moving from birefnet to biref) to avoid conflicts with Hub internal behavior, while preserving backward compatibility for already-published repos.

Changes:

• Update BiRefNet’s declared Hub tags from ["nobg", "birefnet"] to ["nobg", "biref"].
• Update AutoModel and the AutoProcessor legacy fallback to recognize both biref and birefnet tags.
• Bump library version to 0.2.5.

Reviewed changes

Copilot reviewed 3 out of 3 changed files in this pull request and generated no comments.

File	Description
src/nobg/birefnet/modeling_birefnet.py	Changes the model’s Hub tag to biref to avoid Hub tag collisions.
src/nobg/auto.py	Accepts both biref and legacy birefnet tags for model/processor dispatch.
src/nobg/__init__.py	Bumps package version to 0.2.5 (Hatch dynamic version source).

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[chonk-lain]

minor follow up, to avoid any friction in the future i should have gone for nobg-birefnet instead of just biref.
this way we can have a solid template that would not give us any friction in the future.
will deploy another pr to implement this 🫡