Generate: logits processors are doctested and fix broken doctests (#25692)

* shorter example

* add logits processors to doctests

* remove file from conflict?

* tmp commit

* Fix broken tests; Shorter sampling tests

* Apply suggestions from code review
Co-authored-by: Arthur <48595927+ArthurZucker@users.noreply.github.com>

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Co-authored-by: Arthur <48595927+ArthurZucker@users.noreply.github.com>

utils/not_doctested.txt

@@ -371,7 +371,6 @@ src/transformers/generation/beam_constraints.py
 src/transformers/generation/beam_search.py
 src/transformers/generation/flax_logits_process.py
 src/transformers/generation/flax_utils.py
-src/transformers/generation/logits_process.py
 src/transformers/generation/stopping_criteria.py
 src/transformers/generation/streamers.py
 src/transformers/generation/tf_logits_process.py