Bump prettier-plugin-svelte from 2.6.0 to 2.9.0

Bumps [prettier-plugin-svelte](https://github.com/sveltejs/prettier-plugin-svelte) from 2.6.0 to 2.9.0.
- [Release notes](https://github.com/sveltejs/prettier-plugin-svelte/releases)
- [Changelog](https://github.com/sveltejs/prettier-plugin-svelte/blob/master/CHANGELOG.md)
- [Commits](https://github.com/sveltejs/prettier-plugin-svelte/commits)

---
updated-dependencies:
- dependency-name: prettier-plugin-svelte
  dependency-type: direct:development
  update-type: version-update:semver-minor
...

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