chore(deps-dev): bump the astro group across 1 directory with 2 updates

Bumps the astro group with 2 updates in the / directory: [@astrojs/mdx](https://github.com/withastro/astro/tree/HEAD/packages/integrations/mdx) and [astro](https://github.com/withastro/astro/tree/HEAD/packages/astro).


Updates `@astrojs/mdx` from 3.1.5 to 3.1.6
- [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/[email protected]/packages/integrations/mdx)

Updates `astro` from 4.15.1 to 4.15.6
- [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: "@astrojs/mdx"
  dependency-type: direct:development
  update-type: version-update:semver-patch
  dependency-group: astro
- dependency-name: astro
  dependency-type: direct:development
  update-type: version-update:semver-patch
  dependency-group: astro
...

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

package.json

@@ -59,11 +59,11 @@
   },
   "devDependencies": {
     "@astrojs/check": "^0.9.3",
-    "@astrojs/mdx": "^3.1.5",
+    "@astrojs/mdx": "^3.1.6",
     "@rollup/plugin-typescript": "^11.1.6",
     "@typescript-eslint/eslint-plugin": "^7.5.0",
     "@typescript-eslint/parser": "^7.5.0",
-    "astro": "^4.15.1",
+    "astro": "^4.15.6",
     "autoprefixer": "^10.4.20",
     "bootstrap": "^5.3.2",
     "bundlewatch": "^0.4.0",