Removed FlashAttention dependency.

bert_layers.py

@@ -25,10 +25,7 @@ from .bert_padding import (index_first_axis,
                                             unpad_input, unpad_input_only)
 from .configuration_bert import BertConfig
 
-try:
-    from .flash_attn_triton import flash_attn_qkvpacked_func
-except ImportError as e:
-    flash_attn_qkvpacked_func = None
+flash_attn_qkvpacked_func = None
 
 logger = logging.getLogger(__name__)