build(deps): bump astro from 3.1.0 to 4.2.1

Bumps [astro](https://github.com/withastro/astro/tree/HEAD/packages/astro) from 3.1.0 to 4.2.1.
- [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/[email protected]/packages/astro)

---
updated-dependencies:
- dependency-name: astro
  dependency-type: direct:production
  update-type: version-update:semver-major
...

Signed-off-by: dependabot[bot] <[email protected]>

package.json

@@ -18,7 +18,7 @@
     "@astrojs/sitemap": "^3.0.0",
     "@mapbox/rehype-prism": "^0.8.0",
     "@nanostores/react": "^0.4.1",
-    "astro": "^3.1.0",
+    "astro": "^4.2.1",
     "dayjs": "^1.11.10",
     "dotenv": "^16.3.1",
     "escape-html": "^1.0.3",