build(deps): bump the astro-packages group with 3 updates (#301)

Bumps the astro-packages group with 3 updates: [@astrojs/mdx](https://github.com/withastro/astro/tree/HEAD/packages/integrations/mdx), [@astrojs/sitemap](https://github.com/withastro/astro/tree/HEAD/packages/integrations/sitemap) and [astro](https://github.com/withastro/astro/tree/HEAD/packages/astro).


Updates `@astrojs/mdx` from 4.3.4 to 4.3.6
- [Release notes](https://github.com/withastro/astro/releases)
- [Changelog](https://github.com/withastro/astro/blob/main/packages/integrations/mdx/CHANGELOG.md)
- [Commits](https://github.com/withastro/astro/commits/@astrojs/mdx@4.3.6/packages/integrations/mdx)

Updates `@astrojs/sitemap` from 3.5.1 to 3.6.0
- [Release notes](https://github.com/withastro/astro/releases)
- [Changelog](https://github.com/withastro/astro/blob/main/packages/integrations/sitemap/CHANGELOG.md)
- [Commits](https://github.com/withastro/astro/commits/@astrojs/sitemap@3.6.0/packages/integrations/sitemap)

Updates `astro` from 5.13.5 to 5.14.1
- [Release notes](https://github.com/withastro/astro/releases)
- [Changelog](https://github.com/withastro/astro/blob/main/packages/astro/CHANGELOG.md)
- [Commits](https://github.com/withastro/astro/commits/astro@5.14.1/packages/astro)

---
updated-dependencies:
- dependency-name: "@astrojs/mdx"
  dependency-version: 4.3.6
  dependency-type: direct:production
  update-type: version-update:semver-patch
  dependency-group: astro-packages
- dependency-name: "@astrojs/sitemap"
  dependency-version: 3.6.0
  dependency-type: direct:production
  update-type: version-update:semver-minor
  dependency-group: astro-packages
- dependency-name: astro
  dependency-version: 5.14.1
  dependency-type: direct:production
  update-type: version-update:semver-minor
  dependency-group: astro-packages
...

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Author: dependabot[bot]