Support nextConfig.images.formats

[ascorbic]

The next/image edge function returns AVIF images if the browser supports it. However it can be slower to process than other formats, so may time out (e.g. #687 (comment) ). In sites that need to use large images, a workaround could be to add support for specifying supported image formats, and not rewrite to AVIF format if it is disabled. The value could be read from the config and included in the edge function.

[hughrawlinson]

I didn't realize that the nextconfig.images.formats config wasn't supported in Netlify, this explains a lot! Thanks! 😄 Subscribing to this issue.