build(deps): bump svelte and svelte-routing in /mythtv/html/frontend

Bumps [svelte](https://github.com/sveltejs/svelte/tree/HEAD/packages/svelte) and [svelte-routing](https://github.com/EmilTholin/svelte-routing). These dependencies needed to be updated together.

Updates `svelte` from 3.49.0 to 4.2.19
- [Release notes](https://github.com/sveltejs/svelte/releases)
- [Changelog](https://github.com/sveltejs/svelte/blob/svelte@4.2.19/packages/svelte/CHANGELOG.md)
- [Commits](https://github.com/sveltejs/svelte/commits/svelte@4.2.19/packages/svelte)

Updates `svelte-routing` from 1.6.0 to 1.11.0
- [Changelog](https://github.com/EmilTholin/svelte-routing/blob/master/CHANGELOG.md)
- [Commits](https://github.com/EmilTholin/svelte-routing/commits)

---
updated-dependencies:
- dependency-name: svelte
  dependency-type: direct:development
- dependency-name: svelte-routing
  dependency-type: direct:production
...

Signed-off-by: dependabot[bot] <support@github.com>