如何在基于keras的神经网络中使用tensorflow one热编码？

import tensorflow as tf
from tensorflow import keras

(x_train, y_train), (x_test, y_test) = keras.datasets.mnist.load_data()

# 将输入数据归一化到0到1之间
x_train = x_train / 255.0
x_test = x_test / 255.0

# 将标签进行One-hot编码
y_train = tf.one_hot(y_train, depth=10)
y_test = tf.one_hot(y_test, depth=10)

model = keras.Sequential([
    keras.layers.Flatten(input_shape=(28, 28)),
    keras.layers.Dense(128, activation='relu'),
    keras.layers.Dense(10, activation='softmax')
])

model.compile(optimizer='adam',
              loss='categorical_crossentropy',
              metrics=['accuracy'])

model.fit(x_train, y_train, epochs=10, batch_size=32, validation_data=(x_test, y_test))