fix: create new URL when calling goto(...), to handle case where URL is mutated

[Rich-Harris]

fixes #13187. should probably get a test before we merge it and don't have time for it just now, but wanted to push the fix up anyway

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[eltigerchino]

Added the test

[Leonidaz]

no big deal but thought maybe it's worth saving creating another instance if one was already created.

Suggested change

	url = new URL(resolve_url(url));
	const resolved = resolve_url(url);
	// force new URL for page.url reactivity
	url = url === resolved ? new URL(resolved) : resolved;