Fix layer_outputs handling: transformers 5.x returns tensor, not tuple

Fix rotary_emb location - use model level attribute

Fix rotary_emb location - get from layer self_attn

Add position_embeddings for transformers 5.x decoder layer compatibility

Fix get_usable_length -> get_seq_length for transformers 5.x

Fix from_legacy_cache compatibility for transformers 5.x

Upload migrated model for transformers 5.0+ compatibility

initial commit