[WebGPU] fix compile on latest 24.02 (microsoft#24364)

Author: guschmue

onnxruntime/core/providers/webgpu/nn/activation_util.h

@@ -4,6 +4,7 @@
 #pragma once
 
 #include <string>
+#include <cinttypes>
 
 namespace onnxruntime {
 namespace webgpu {
@@ -12,4 +13,4 @@ extern std::string TypeSnippet(uint32_t component, std::string data_type);
 extern std::string BiasSnippet(bool has_bias);
 
 }  // namespace webgpu
-}  // namespace onnxruntime
+}  // namespace onnxruntime