Allow "edge" as a runtime for pages in the Pages Router

[joulev]

What?

Currently pages on the Pages Router only accept "experimental-edge", not "edge". If you use "edge", there will be a build error.

This is contrary to the documentation, which states

You can explicitly set the runtime on a per-page basis by modifying the config, for example:

// pages/index.js
export const config = {
  runtime: 'nodejs', // or "edge"
}
 
export const getServerSideProps = async () => {}

– source

This PR allows "edge" to be used as the runtime for Pages Router pages.

Why?

Either the documentation is wrong, or the "edge" check should be removed. Since in #50701, the // or "edge" phrase was explicitly added to that part, I suppose the team decided already to fully stabilise the edge runtime everywhere, so I decided to make the PR to remove the "edge" check.

If the documentation is wrong and the edge runtime should still be marked as experimental, feel free to close this PR but please also update the documentation in that case.

How?

I simply removed the "edge" checks. Using "experimental-edge" in pages should now result in a warning but things should still work (same as Edge API Routes).

Fixes #65945

[ijjk]

Allow CI Workflow Run

• approve CI run for commit: 6ebdd91

Note: this should only be enabled once the PR is ready to go and can only be enabled by a maintainer

[ijjk]

Allow CI Workflow Run

• approve CI run for commit: 6ebdd91

Note: this should only be enabled once the PR is ready to go and can only be enabled by a maintainer

[leerob]

Thank you! Good flag. I would prefer to update the docs here to remove that bit. Pulling forward in #65962 🙏

[joulev]

Thank you!