Fix the vocabulary_dtype in keras.layers.IntegerLookup() (#21587)

Author: ILCSFNO

keras/src/layers/preprocessing/integer_lookup.py

@@ -76,8 +76,9 @@ class IntegerLookup(IndexLookup):
             If passing a file path, the file should contain one line per term
             in the vocabulary. If this argument is set,
             there is no need to `adapt()` the layer.
-        vocabulary_dtype: The dtype of the vocabulary terms, for example
-            `"int64"` or `"int32"`. Defaults to `"int64"`.
+        vocabulary_dtype: The dtype of the vocabulary terms.
+            Only `vocabulary_dtype='int64'` is supported at this time.
+            Defaults to `"int64"`.
         idf_weights: Only valid when `output_mode` is `"tf_idf"`.
             A tuple, list, 1D NumPy array, or 1D tensor or the same length
             as the vocabulary, containing the floating point inverse document