silence xformers warning, should also update to torch native attn flash, but lazy

romatch/models/transformer/layers/block.py

@@ -29,7 +29,7 @@ try:
 
     XFORMERS_AVAILABLE = True
 except ImportError:
-    logger.warning("xFormers not available")
+    # logger.warning("xFormers not available")
     XFORMERS_AVAILABLE = False