fix test error

Author: susanbao

src/maxdiffusion/tests/wan_transformer_test.py

@@ -316,7 +316,7 @@ def test_get_qt_provider(self, mock_qt_rule):
         module_path=".*",  # Apply to all modules
         weight_qtype=jnp.float8_e4m3fn,
         act_qtype=jnp.float8_e4m3fn,
-        bwd_qtype=jnp.float8_e5m2,
+        bwd_qtype=jnp.float8_e4m3fn,
         bwd_use_original_residuals=True,
         disable_channelwise_axes=True,  # per_tensor calibration
         weight_calibration_method=config_fp8_full.quantization_calibration_method,