Remove unused variables // adam & adamw (keras-team#444)

* Adam remove unused vars

* Adamw remove unused vars

Author: Frightera

keras_core/optimizers/adam.py

@@ -108,8 +108,6 @@ def build(self, var_list):
 
     def update_step(self, gradient, variable, learning_rate):
         """Update step given gradient and the associated model variable."""
-        beta_1_power = None
-        beta_2_power = None
         lr = ops.cast(learning_rate, variable.dtype)
         gradient = ops.cast(gradient, variable.dtype)
         local_step = ops.cast(self.iterations + 1, variable.dtype)

keras_core/optimizers/adamw.py

@@ -124,8 +124,6 @@ def build(self, var_list):
 
     def update_step(self, gradient, variable, learning_rate):
         """Update step given gradient and the associated model variable."""
-        beta_1_power = None
-        beta_2_power = None
         lr = ops.cast(learning_rate, variable.dtype)
         gradient = ops.cast(gradient, variable.dtype)
         local_step = ops.cast(self.iterations + 1, variable.dtype)