Upgrade dependencies - nextra v3.0.2

Use the latest versions of the following packages:

- next ~14.2.5~ to 14.2.14
- nextra ~2.13.4~ to 3.0.2
- nextra-theme-docs ~2.13.4~ to 3.0.2

> [!WARNING]
> **Upgrading to nextra v3 has breaking changes from nextra v2.**
> Test updates thoroughly before committing changes.