add Tuple as possible type hint for EvalPredictions label_ids

[ameasure]

What does this PR do?

This adds Tuple as a type hint for the label_ids attribute in EvalPredictions. It is a valid type that label_ids can have.

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@stas00

[stas00]

If that's the case, then for consistency the following 2 classes should have the proposed changed as well.

@sgugger, what do you think?

[sgugger]

Thanks for fixing the type!
I agree with @stas00 remark on the two following classes.