Fix post processing RF-DETR

[yonigozlan]

What does this PR do?

The post processing used for RF-DETR was the same as the one for DETR, which is incorrect. We now use similar post-processing for both detection and segmentation as the original repo.
The preprocessing also introduced some differences with the original one as the original preprocessing rescale then resize, and we usually do the opposite in Transformers. We are now aligned with the original repo, and the remaining very small differences are due to differences in how we convert the images from pil to torch (pil_to_tensor then scale compared to to_tensor in the original repo), although this shouldn't affect the quality of the predictions.

Cc @molbap @SkalskiP

[HuggingFaceDocBuilderDev]

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[yonigozlan]

run-slow: rf_detr

[github-actions]

Workflow Run ⚙️

This comment contains run-slow, running the specified jobs:

models: ["models/rf_detr"]
quantizations: []

[github-actions]

CI Results

Workflow Run ⚙️

Commit Info

Context	Commit	Description
RUN	02df063c	workflow commit (merge commit)
PR	14dd7eb7	branch commit (from PR)
main	73d91596	base commit (on main)

✅ No failing test specific to this PR 🎉 👏 !

[molbap]

Thanks for fixing, let's make sure Expectations fall in reasonable deviations from original implem, then should be good. The new post processing seems in line with the rest of the DETR family. left two small comments

[github-actions]

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

run-slow: auto, lw_detr, rf_detr

[yonigozlan]

run-slow: rf_detr, lw_detr

[github-actions]

Workflow Run ⚙️

This comment contains run-slow, running the specified jobs:

models: ["models/lw_detr", "models/rf_detr"]
quantizations: []

[github-actions]

CI Results

Workflow Run ⚙️

Commit Info

Context	Commit	Description
RUN	c8038f4d	workflow commit (merge commit)
PR	80832327	branch commit (from PR)
main	b797f0d4	base commit (on main)

✅ No failing test specific to this PR 🎉 👏 !