Declaring `classifier_dropout` in model config but not using it
The PEGASUS model is declaring `classifier_dropout` in the model config:

https://github.com/huggingface/transformers/blob/546dc24e0883e5e9f5eb06ec8060e3e6ccc5f6d7/src/transformers/models/pegasus/configuration_pegasus.py#L128

But the model never uses it. This is a bug IMO.

In contrast mBART defines it:

https://github.com/huggingface/transformers/blob/546dc24e0883e5e9f5eb06ec8060e3e6ccc5f6d7/src/transformers/models/mbart/configuration_mbart.py#L127

and uses it:

https://github.com/huggingface/transformers/blob/546dc24e0883e5e9f5eb06ec8060e3e6ccc5f6d7/src/transformers/models/mbart/modeling_mbart.py#L1395

If wanted I can provide a fix (non breaking) as a PR.
Tagging @NielsRogge<|||||>also see this issue: #12781<|||||>@NielsRogge what do you think?<|||||>Well, since Pegasus does not have SequenceClassification or TokenClassification the `classifier_dropout` could be just removed from the config.<|||||>fixed in PR - closing