Migrate references to jax.lib.xla_extension to jax.extend.

PiperOrigin-RevId: 788868759

Author: danielsuo

pathwaysutils/test/proxy_backend_test.py

@@ -20,6 +20,7 @@
 from jax.lib.xla_extension import ifrt_proxy
 from pathwaysutils import proxy_backend
 
+
 from absl.testing import absltest