Add AdamW optimizer

src/TensorFlowNET.Keras/Optimizers/AdamW.cs

@@ -1,4 +1,4 @@
-namespace Tensorflow.Keras.Optimizers
+namespace Tensorflow.Keras.Optimizers
 {
     public class AdamW : Adam
     {
@@ -22,9 +22,6 @@
 
         protected Operation _decay_weights_op(IVariableV1 var, float learning_rate, Dictionary<DeviceDType, Dictionary<string, Tensor>> apply_state)
         {
-            var device_dtype = new DeviceDType();
-            device_dtype.DType = var.dtype;
-            device_dtype.Device = var.Device;
             bool do_decay = _do_use_weight_decay(var.Name);
             if (do_decay) return var.assign_add(
                 -learning_rate * var.AsTensor() * apply_state[deType]["weight_decay"]);