In SPA mode, navigating to a page that triggers a redirect inside `onUpdate` fails silently

[fnimick]

Description
Navigating to a page in onUpdate via await goto(....) fails if that page has a client-side load function that calls redirect().

If applicable, a MRE
https://stackblitz.com/edit/superforms-2-testing-qf9uxu?file=src%2Froutes%2F%2Bpage.svelte

In this example, calling await goto('/target'); fails because target/+page.ts has a load function that throws a redirect.

Either calling cancel() first, or instead calling goto('/second-target') which does not have a redirect, works fine.

[ciscoheat]

Fixed now in 2.6.1, forked the project and tested on Stackblitz.