Fix deebert tests
# [Codecov](https://codecov.io/gh/huggingface/transformers/pull/6102?src=pr&el=h1) Report
> Merging [#6102](https://codecov.io/gh/huggingface/transformers/pull/6102?src=pr&el=desc) into [master](https://codecov.io/gh/huggingface/transformers/commit/06834bc33255f5fb8fabb72c9ff114764b3c7ce5&el=desc) will **increase** coverage by `0.00%`.
> The diff coverage is `n/a`.

[![Impacted file tree graph](https://codecov.io/gh/huggingface/transformers/pull/6102/graphs/tree.svg?width=650&height=150&src=pr&token=9qOlN6Hb1c)](https://codecov.io/gh/huggingface/transformers/pull/6102?src=pr&el=tree)

```diff
@@           Coverage Diff           @@
##           master    #6102   +/-   ##
=======================================
  Coverage   77.77%   77.77%           
=======================================
  Files         146      146           
  Lines       26325    26325           
=======================================
+ Hits        20474    20475    +1     
+ Misses       5851     5850    -1     
```


| [Impacted Files](https://codecov.io/gh/huggingface/transformers/pull/6102?src=pr&el=tree) | Coverage Δ | |
|---|---|---|
| [src/transformers/generation\_tf\_utils.py](https://codecov.io/gh/huggingface/transformers/pull/6102/diff?src=pr&el=tree#diff-c3JjL3RyYW5zZm9ybWVycy9nZW5lcmF0aW9uX3RmX3V0aWxzLnB5) | `86.46% <0.00%> (+0.25%)` | :arrow_up: |

------

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