Handles incompatible quantization mode for ReversibleEmbedding (#2435)

* Handles incompatible quantization mode for ReversibleEmbedding

* fix grammar

Author: JyotinderSingh

keras_hub/src/layers/modeling/reversible_embedding.py

@@ -245,6 +245,12 @@ def abs_max_quantize(inputs, axis):
                 inputs, axis=axis, to_numpy=True
             )
 
+        if mode != "int8":
+            raise NotImplementedError(
+                "Invalid quantization mode. Expected 'int8'. "
+                f"Received: quantization_mode={mode}"
+            )
+
         embeddings_shape = (self.input_dim, self.output_dim)
         if mode == "int8":
             embeddings, embeddings_scale = abs_max_quantize(