Make dawn node functions writable

They are writable in the browser but not in dawn node.
This breaks compat in the CTS which works by wrapping
requestAdapter to insert `compatibilityMode: true`
into the adapter descriptor in src/common/util/navigator_gpu.ts

Bug: dawn:2151
Change-Id: Ic8a8f20c770c1a602ed03d07ca19c349be4c859e
Reviewed-on: https://dawn-review.googlesource.com/c/dawn/+/163363
Commit-Queue: Gregg Tavares <[email protected]>
Kokoro: Kokoro <[email protected]>
Reviewed-by: Ben Clayton <[email protected]>

Author: greggman

src/dawn/node/interop/WebGPU.cpp.tmpl

@@ -151,7 +151,7 @@ Wrappers* Wrappers::instance = nullptr;
         InstanceMethod("keys", &W{{$.Name}}::keys),
 {{-  end}}
 {{-  range $m := $methods}}
-        InstanceMethod("{{$m.Name}}", &W{{$.Name}}::{{$m.Name}}),
+        InstanceMethod("{{$m.Name}}", &W{{$.Name}}::{{$m.Name}}, static_cast<napi_property_attributes>(napi_writable | napi_configurable)),
 {{-  end}}
 {{-  range $a := $attributes}}
 {{-   if not (HasAnnotation $a "SameObject")}}