Update keras/src/utils/jax_layer.py

Co-authored-by: gemini-code-assist[bot] <176961590+gemini-code-assist[bot]@users.noreply.github.com>

Author: wenyi-guo

keras/src/utils/jax_layer.py

@@ -22,6 +22,8 @@
 
 
 def standardize_pytree_collections(pytree):
+    if isinstance(pytree, (str, bytes)):
+        return pytree
     if isinstance(pytree, collections.abc.Mapping):
         return {k: standardize_pytree_collections(v) for k, v in pytree.items()}
     elif isinstance(pytree, collections.abc.Sequence):