Add eslint-plugin-vitest

[kieranhall]

By adding a dependency to eslint-plugin-vitest, we can reduce our own overrides configuration in our projects that use Vitest for testing.

          Maybe we could add this to our [eslint config repo](https://github.com/dusk-network/eslint-config) as an additional config that we can import?

Originally posted by @ascartabelli in dusk-network/rusk#1486 (comment)

[kieranhall]

Note that we also use Testing Library and may want to also look at this plugin for working with that.

[kieranhall]

Note that we also use Testing Library and may want to also look at this plugin for working with that.

The plugin is not providing a preset for working with Svelte yet. See: testing-library/eslint-plugin-testing-library#80