Fix AutoModelTest.test_model_from_pretrained
# What does this PR do?

From @Narsil 

> Hmmmm it's because of safetensors is installed in that environement and it's loading the safetensors weights which have indeed 1 less unexpected keys (the duplicated key was removed)

I tried `gpt2` and `roberta-base`, they also have similar issues, on some keys among `missing_keys`, `unexpected_keys` etc..
I decided to stop trying and just give a condition.
The other way to fix would be to modify the original files to remove the duplicated layer. I think that was suggested by @sgugger .

I personally am ok with the proposed fix, it does seem the easiest route.<|||||>_The documentation is not available anymore as the PR was closed or merged._