Fix a typo (add a coma)
Author: PolarisRisingWar
Pull request: yes

As mentioned: https://github.com/huggingface/transformers/issues/16277

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Fixes   #16277 
Fixed a typo that missed a coma.
@gante  As you said, I opened a pull request, and I hope I've made it in a correct way.

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Comments:
_The documentation is not available anymore as the PR was closed or merged._

Awesome, thanks @PolarisRisingWar! 🚀