optional kernel features warning: an attribute specifier sequence in this position is a C++23 extension

[AlexeySachkov]

SYCL-CTS/tests/optional_kernel_features/kernel_features_common.h

Lines 336 to 342 in 9691bc0

	} else if constexpr (CallType ==
	call_attribute_type::external_decorated_with_attr) {
	return [acc] [[sycl::device_has(AnotherFeatureAspect)]] {
	use_feature_function_external_decorated<FeatureTypeT, FeatureAspectT>(
	acc);
	};
	} else if constexpr (CallType == call_attribute_type::non_decorated) {

Example of build log:

[560/1195] Building CXX object tests/optional_kernel_features/CMakeFiles/test_optional_kernel_features_objects.dir/kernel_features_sub_group_size_exceptions.cpp.o
In file included from ../tests/optional_kernel_features/kernel_features_sub_group_size_exceptions.cpp:26:
../tests/optional_kernel_features/kernel_features_common.h:338:18: warning: an attribute specifier sequence in this position is a C++23 extension [-Wc++23-extensions]
  338 |     return [acc] [[sycl::device_has(AnotherFeatureAspect)]] {
      |                  ^
../tests/optional_kernel_features/kernel_features_common.h:353:16: warning: an attribute specifier sequence in this position is a C++23 extension [-Wc++23-extensions]
  353 |     return [=] [[sycl::device_has(FeatureAspectT)]] {
      |                ^
../tests/optional_kernel_features/kernel_features_common.h:359:16: warning: an attribute specifier sequence in this position is a C++23 extension [-Wc++23-extensions]
  359 |     return [=] [[sycl::device_has(AnotherFeatureAspect)]] {
      |                ^
3 warnings generated.