support to_static for SpectralNorm (#51622)

* support to_static for SpectralNorm

python/paddle/nn/utils/spectral_norm_hook.py

@@ -23,7 +23,7 @@ __all__ = []
 
 def normal_(x, mean=0.0, std=1.0):
     temp_value = paddle.normal(mean, std, shape=x.shape)
-    x.set_value(temp_value)
+    paddle.assign(temp_value, x)
     return x
 
 
@@ -61,7 +61,7 @@ class SpectralNorm:
         if do_power_iteration:
             with paddle.no_grad():
                 for _ in range(self.n_power_iterations):
-                    v.set_value(
+                    paddle.assign(
                         F.normalize(
                             paddle.matmul(
                                 weight_mat,
@@ -71,15 +71,17 @@ class SpectralNorm:
                             ),
                             axis=0,
                             epsilon=self.eps,
-                        )
+                        ),
+                        v,
                     )
 
-                    u.set_value(
+                    paddle.assign(
                         F.normalize(
                             paddle.matmul(weight_mat, v),
                             axis=0,
                             epsilon=self.eps,
-                        )
+                        ),
+                        u,
                     )
                 if self.n_power_iterations > 0:
                     u = u.clone()