Fix some test issues when WebGPU and DML are enabled in the same build

onnxruntime/core/providers/dml/DmlExecutionProvider/src/ExecutionProvider.cpp

@@ -781,7 +781,10 @@ namespace Dml
                 // this branch could be reached with a bad custom operator or malformed file. If
                 // a legitimate case reaches here and DML needs to support a new input/output type
                 // besides tensors, then remove the assert.
-                assert(false);
+
+                // If the model has nodes that use Optional we will arrive here. It's a valid ONNX model but 
+                // TryGetTensorDataType doesn't handle Optional.              
+                // assert(false);
                 nodeContainsSupportedDataTypes = false;
                 return;
             }

onnxruntime/test/contrib_ops/matmul_4bits_test.cc

@@ -527,18 +527,20 @@ void RunTest(int64_t M, int64_t N, int64_t K, int64_t block_size, bool has_zerop
   if (std::is_same_v<T, MLFloat16>) {
 #ifdef USE_CUDA
     execution_providers.push_back(DefaultCudaExecutionProvider());
+    RunTest<MLFloat16>(opts, std::move(execution_providers));
 #endif
 #ifdef USE_ROCM
     execution_providers.push_back(DefaultRocmExecutionProvider());
+    RunTest<MLFloat16>(opts, std::move(execution_providers));
 #endif
 #ifdef USE_DML
     execution_providers.push_back(DefaultDmlExecutionProvider());
+    RunTest<MLFloat16>(opts, std::move(execution_providers));
 #endif
 #ifdef USE_WEBGPU
     execution_providers.push_back(DefaultWebGpuExecutionProvider());
-#endif
-
     RunTest<MLFloat16>(opts, std::move(execution_providers));
+#endif
   } else {
 #ifdef USE_ROCM
     execution_providers.push_back(DefaultRocmExecutionProvider());

onnxruntime/test/providers/cpu/math/softmax_test.cc

@@ -61,7 +61,8 @@ TEST(SoftmaxOperator, webgpu_nan) {
   test.AddOutput<float>("Y", dimensions, expected_result);
 
   // explicitly disable for EPs that do not handle NaN
-  test.Run(OpTester::ExpectResult::kExpectSuccess, "", {kCpuExecutionProvider, kCoreMLExecutionProvider});
+  test.Run(OpTester::ExpectResult::kExpectSuccess, "",
+           {kCpuExecutionProvider, kCoreMLExecutionProvider, kDmlExecutionProvider});
 }
 #endif