Fix Keras 3 version check (#1328)

* Fix Keras 3 version check

* Fix Keras 3 version check

* Update version check

* Raise error if Keras is not compatible with TF

keras_nlp/backend/config.py

@@ -65,11 +65,19 @@
 
 def detect_if_tensorflow_uses_keras_3():
     # We follow the version of keras that tensorflow is configured to use.
-    from tensorflow import keras
-
-    # Note that only recent versions of keras have a `version()` function.
-    if hasattr(keras, "version") and keras.version().startswith("3."):
-        return True
+    try:
+        from tensorflow import keras
+
+        # Note that only recent versions of keras have a `version()` function.
+        if hasattr(keras, "version") and keras.version().startswith("3."):
+            return True
+    except:
+        raise ValueError(
+            "Unable to import `keras` with `tensorflow`.  Please check your "
+            "Keras and Tensorflow version are compatible; Keras 3 requires "
+            "TensorFlow 2.15 or later. See keras.io/getting_started for more "
+            "information on installing Keras."
+        )
 
     # No `keras.version()` means we are on an old version of keras.
     return False