@ory/next: use of headers() leads to warnings/errors

[jonas-jonas]

Preflight checklist

• [x] I could not find a solution in the existing issues, docs, nor discussions.
• [x] I agree to follow this project's Code of Conduct.
• [x] I have read and am following this repository's Contribution Guidelines.
• [ ] I have joined the Ory Community Slack.
• [ ] I am signed up to the Ory Security Patch Newsletter.

Ory Network Project

No response

Describe the bug

It seems that using await here may make it compatible with Next.js v15. Reference: https://nextjs.org/docs/messages/sync-dynamic-apis

export function filterRequestHeaders(
  forwardAdditionalHeaders?: string[],
): Headers {
  const filteredHeaders = new Headers()
  headers().forEach((value, key) => {
    const isValid =
      defaultForwardedHeaders.includes(key) ||
      (forwardAdditionalHeaders ?? []).includes(key)
    if (isValid) filteredHeaders.set(key, value)
  })

  return filteredHeaders
}

Error log: [Error: Route "/api/.ory/[...paths]" used headers().forEach(...). headers() should be awaited before using its value. Learn more: https://nextjs.org/docs/messages/sync-dynamic-apis]

Reproducing the bug

Relevant log output

Relevant configuration

Version

master

On which operating system are you observing this issue?

None

In which environment are you deploying?

None

Additional Context

No response