* Added 'UpdateEmbeddingCallback`
    * `DynamicEmbedding` layer allows for the continuous updating of the
      vocabulary and embeddings during the training process. This layer
      maintains a hash table to track the most up-to-date vocabulary based on
      the inputs received by the layer and the eviction policy. When this layer
      is used with an `UpdateEmbeddingCallback`, which is a time-based callback,