docs: fix external data loading path (#5109)

The link to External Data Loading on the [Query
Integration](https://tanstack.com/router/latest/docs/integrations/query)
page currently throws a 404.

<!-- This is an auto-generated comment: release notes by coderabbit.ai
-->

## Summary by CodeRabbit

* **Documentation**
* Corrected a link in the Router integrations guide to point to the
proper External Data Loading page in the React framework section. This
fixes navigation from that note and ensures readers can access the
referenced guidance without errors. No functional changes to the
product; content remains otherwise unchanged and reduces confusion.

<!-- end of auto-generated comment: release notes by coderabbit.ai -->

Author: KiwiKilian

docs/router/integrations/query.md

@@ -4,7 +4,7 @@ title: TanStack Query Integration
 ---
 
 > [!IMPORTANT]
-> This integration automates SSR dehydration/hydration and streaming between TanStack Router and TanStack Query. If you haven't read the standard [External Data Loading](../framework/react/guide/external-data-loading.md) guide, start there.
+> This integration automates SSR dehydration/hydration and streaming between TanStack Router and TanStack Query. If you haven't read the standard [External Data Loading](../../framework/react/guide/external-data-loading.md) guide, start there.
 
 ## What you get