🍿 Minor Changes

• #626 5dd22b8 Thanks @delucis! - Throw an error for duplicate MDX or sitemap integrations

• #615 7b75b3e Thanks @delucis! - Bump minimum required Astro version to 3.0

  ⚠️ BREAKING CHANGE Astro v2 is no longer supported. Make sure you update Astro and any other integrations at the same time as updating Starlight.