### Description
The redirect responses from the redirect function do not contain a message body. This is in conflict with the RFCs below and causes Traefik (a reverse proxy) to invalidate the responses. In this pull request, I add a response body to the redirect responses.
### References
- https://datatracker.ietf.org/doc/html/rfc7230#section-3.3
> All 1xx (Informational), 204 (No Content), and 304 (Not Modified) responses must not include a message-body. All other responses do include a message-body, although the body may be of zero length.
- https://datatracker.ietf.org/doc/html/rfc7231#section-6.4.3
> The server's response payload usually contains a short hypertext note with a hyperlink to the different URI(s).
- traefik/traefik#4456
- https://github.com/auth0/nextjs-auth0/pull/399
This decreases the body size limit that triggers a warning from 5MB -> 4MB, which provides a little more wiggle room. Certain things like using base64 on body, headers, path, etc can cause the response to be larger than initially calculated.
Initial PR: https://github.com/vercel/next.js/pull/26831
This PR adds a warning when api responses exceed 5mb since this will end up failing once deployed. In a future version this scenario will throw an error.
## Bug
- [x] Integration tests added
## Documentation / Examples
- [x] Make sure the linting passes
