Unable to send custom response headers

[ChristianRich]

I have a requirement to set cookies and response headers for my Azure/Apollo 4 GraphQL API.
Example resolver setting a cookie and a custom response header.

import type { Context } from "@azure/functions";

const resolvers = {
  Query: {
    hello: (_: unknown, args: unknown, context: Context): String => {
      const myCookie = cookie.serialize("my-cookie", `test-${Math.random()}`, {
        maxAge: 86400,
        httpOnly: true,
        sameSite: "none",
        secure: false,
      });

      context?.res?.headers["Set-Cookie"] = myCookie;
      context?.res?.headers["x-correlation-id"] = "1234";
      return "hello";
    },
  },
};

However, this will currently not work since apollo-server-integration-azure-functions ignores context.res?.headers when serving the API response to the Azure Function.

https://github.com/apollo-server-integrations/apollo-server-integration-azure-functions/blob/main/src/index.ts#L59

However this change makes it work:

2f9aec9

Is this an oversight or am I using the library incorrectly?