Fix blip2 tests (#38510)
* fix 1: not sure
* fix 2: _supports_flex_attn = False
* fix 3: embedding_output = self.layernorm(query_embeds.to(self.layernorm.weight.dtype))
* fix 4: query_embeds = query_embeds.to(self.layernorm.weight.dtype)
* fix 5: text_embeds = text_embeds.to(dtype=torch.float16)
* fix 5: question_embeds.to(dtype=torch.float16)
* fix 6: text_embeds = text_embeds.to(dtype=self.itm_head.weight.dtype)
* fix 7: image_embeds and question_embeds
* fix 8: fix other 2 fp16 tests
* fix 9: fix T5 OOM
* fix 10: fix T5 OOM
* fix 11: fix T5
* fix 11: fix T5 beam
* fix 12: _supports_sdpa=False
* fix 12: style and expect
* revert
* revert
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Co-authored-by: ydshieh <ydshieh@users.noreply.github.com>
