Create an api route manifest

[conico974]

For this case we need to create an api-route manifest to properly check

opennextjs-aws/packages/open-next/src/core/routingHandler.ts

Lines 150 to 155 in 5b314b1

	// Api routes are not present in the routes manifest except if they're not behind /api
	// /api even if it's a page route doesn't get generated in the manifest
	// Ideally we would need to properly check api routes here
	const isApiRoute =
	internalEvent.rawPath === apiPrefix ||
	internalEvent.rawPath.startsWith(`${apiPrefix}/`);

[vicb]

Thanks for the issue.

It would be nice to add an e2e for API routes in the pages-router examples as part of this effort.

[conico974]

Fixed in #875