Fix DeiT doc tets
# What does this PR do?

Fixes failing doctest for DeiT cause by copy-pasta from the PT model. 

The predicted class is determinstic with the set seed. However, as RNG for pytorch and tensorflow are different, it's a different class than in the pytorch Deit doctest. 

## Before submitting
- [x] This PR fixes a typo or improves the docs (you can dismiss the other checks if that's the case).
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      Pull Request section?
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- [ ] Did you write any new necessary tests?
_The documentation is not available anymore as the PR was closed or merged._<|||||>From the description & the change, it seems to me that Deit has some random OP(s) used in the inference. Is this the case (and if yes, could you share which line that random op is 🙏 ) Thank you.<|||||>Sure :) `DeiTForImageClassification` loaded from the official facebook hub weights will have its head randomly initialized. You can't see it directly in this diff, but there's a comment above on line L928 mentioning this. 