NextJS 13.4 App router why is not-found considered a dynamic component

Question

I'm using NextJS 13.4 with app router. My not found page is located in /app/not-found.tsx which works fine in development. The content of the page is below:

import { HOMEPAGE_ROUTE } from "../consts/routes";
import Link from "next/link";

const NotFound = () => {
  return (
    <div>
      <Link href={HOMEPAGE_ROUTE}>
        <img
          src="/assets/logo.png"
          alt="Logo"
        ></img>
      </Link>

      <h1>Not found</h1>

      <Link href={HOMEPAGE_ROUTE}>
        Back to home
      </Link>
    </div>
  );
};

export default NotFound;

I am using this to generate a static site with next build which has worked perfectly until adding the not-found page.

However since introducing the not-found page when it comes to deploying to production (firebase in my case) I see the following log:

  Building a Cloud Function to run this application. This is needed due to:
   • non-static component /_not-found

Since I have had no need for dynamic rendering up until this point I would prefer this not be the case. How can I make this component static?

I have read the documentation and can't find any mention of this issue. It was my understanding that as the page did not have any props this page would be static