function has_prerendered_path(manifest, pathname) {
	return (
		manifest._.prerendered_routes.has(pathname) ||
		(pathname.at(-1) === '/' && manifest._.prerendered_routes.has(pathname.slice(0, -1)))
	);
}
Returns `true` if the given path was prerendered
@param {import('@sveltejs/kit').SSRManifest} manifest
@param {string} pathname Should include the base and be decoded