[roberta] add sdpa to roberta and xlm-roberta

[kiszk]

What does this PR do?

This PR enables sdpa in RoBERTa and XLM-RoBERTa. Since sdpa is already added to BERT thru #28802, this PR follows that PR.

Tests for RoBERTa are done by the followings at ModelTesterMixin.

• test_eager_matches_sdpa_generate - test_eager_matches_sdpa_inference_0_float16
• test_eager_matches_sdpa_inference_0_bfloat16
• test_eager_matches_sdpa_inference_0_float32

Fixes #31752

Before submitting

• This PR fixes a typo or improves the docs (you can dismiss the other checks if that's the case).
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• Did you write any new necessary tests?

Who can review?

@ArthurZucker @hackyon