* Add flash-attention-2 backend for ESM-2 Signed-off-by: Peter St. John <pstjohn@nvidia.com> * update extended_attention_mask for fa2 Signed-off-by: Peter St. John <pstjohn@nvidia.com> * add test_flash_attn_2_equivalence test Signed-off-by: Peter St. John <pstjohn@nvidia.com> --------- Signed-off-by: Peter St. John <pstjohn@nvidia.com>