Add NotImplementedError for angle & bartlett on openvino (#21246)

Author: shashaka

keras/src/backend/openvino/numpy.py

@@ -142,6 +142,10 @@ def all(x, axis=None, keepdims=False):
     )
 
 
+def angle(x):
+    raise NotImplementedError("`angle` is not supported with openvino backend")
+
+
 def any(x, axis=None, keepdims=False):
     x = get_ov_output(x)
     if axis is None:
@@ -464,6 +468,12 @@ def average(x, axis=None, weights=None):
     return OpenVINOKerasTensor(mean_ops.output(0))
 
 
+def bartlett(x):
+    raise NotImplementedError(
+        "`bartlett` is not supported with openvino backend"
+    )
+
+
 def bincount(x, weights=None, minlength=0, sparse=False):
     if x is None:
         raise ValueError("input x is None")