src: fix ThrowInvalidURL call in PathToFileURL

Replace `nullptr` with `std::nullopt` when calling `ThrowInvalidURL` in
`PathToFileURL`. This ensures the function receives the correct argument
type and aligns with the expected behavior.

PR-URL: #57141
Reviewed-By: Yagiz Nizipli <yagiz@nizipli.com>
Reviewed-By: Juan José Arboleda <soyjuanarbol@gmail.com>
Reviewed-By: Daniel Lemire <daniel@lemire.me>

Author: danielmbrasil

src/node_url.cc

@@ -161,7 +161,7 @@ void BindingData::PathToFileURL(const FunctionCallbackInfo<Value>& args) {
       ada::parse<ada::url_aggregator>(EncodePathChars(input_str, os), nullptr);
 
   if (!out) {
-    return ThrowInvalidURL(realm->env(), input.ToStringView(), nullptr);
+    return ThrowInvalidURL(realm->env(), input.ToStringView(), std::nullopt);
   }
 
   if (os == OS::WINDOWS && args.Length() > 2 && !args[2]->IsUndefined())