[OpenVINO] Fix pad to accept float scalar constant_values (#22691)

* [OpenVINO] Fix pad to accept float scalar constant_values

* address review comments

* retrigger ci

Author: goyaladitya05

keras/src/backend/openvino/excluded_concrete_tests.txt

@@ -14,7 +14,6 @@ FeatureSpaceTest::test_advanced_usage
 FeatureSpaceTest::test_basic_usage
 FeatureSpaceTest::test_basic_usage_no_strings
 FeatureSpaceTest::test_saving
-GroupedQuantizationParametersTest::test_grouped_weight_shapes_non_divisible
 ImageOpsBehaviorTests::test_affine_transform
 ImageOpsBehaviorTests::test_elastic_transform
 ImageOpsBehaviorTests::test_perspective_transform
@@ -53,7 +52,6 @@ NumpyOneInputOpsCorrectnessTest::test_imag
 NumpyOneInputOpsCorrectnessTest::test_isreal
 NumpyOneInputOpsCorrectnessTest::test_nanmedian
 NumpyOneInputOpsCorrectnessTest::test_real
-QuantizersTest::test_grouped_quantize_with_padding
 RandAugmentTest::test_layer
 RandAugmentTest::test_rand_augment_basic
 RandAugmentTest::test_random_augment_randomness

keras/src/backend/openvino/numpy.py

@@ -3749,7 +3749,9 @@ def pad(x, pad_width, mode="constant", constant_values=None):
                 "provided when `mode == 'constant'`. "
                 f"Received: mode={mode}"
             )
-        if not isinstance(constant_values, int):
+        if not isinstance(
+            constant_values, (int, float, np.integer, np.floating)
+        ):
             raise ValueError(
                 "`pad` operation supports only scalar pad value "
                 "in constant mode with the openvino backend. "