Bump the site-npm group in /site with 2 updates

Bumps the site-npm group in /site with 2 updates: [astro](https://github.com/withastro/astro/tree/HEAD/packages/astro) and [@astrojs/starlight](https://github.com/withastro/starlight/tree/HEAD/packages/starlight).


Updates `astro` from 5.17.3 to 5.18.0
- [Release notes](https://github.com/withastro/astro/releases)
- [Changelog](https://github.com/withastro/astro/blob/astro@5.18.0/packages/astro/CHANGELOG.md)
- [Commits](https://github.com/withastro/astro/commits/astro@5.18.0/packages/astro)

Updates `@astrojs/starlight` from 0.32.6 to 0.37.6
- [Release notes](https://github.com/withastro/starlight/releases)
- [Changelog](https://github.com/withastro/starlight/blob/main/packages/starlight/CHANGELOG.md)
- [Commits](https://github.com/withastro/starlight/commits/@astrojs/starlight@0.37.6/packages/starlight)

---
updated-dependencies:
- dependency-name: astro
  dependency-version: 5.18.0
  dependency-type: direct:production
  update-type: version-update:semver-minor
  dependency-group: site-npm
- dependency-name: "@astrojs/starlight"
  dependency-version: 0.37.6
  dependency-type: direct:production
  update-type: version-update:semver-minor
  dependency-group: site-npm
...

Signed-off-by: dependabot[bot] <support@github.com>

Author: dependabot[bot]

site/package-lock.json

@@ -36,8 +36,8 @@
     "preview": "astro preview"
   },
   "dependencies": {
-    "astro": "^5.2.0",
-    "@astrojs/starlight": "^0.32.0",
+    "astro": "^5.18.0",
+    "@astrojs/starlight": "^0.37.7",
     "astro-mermaid": "^1.0.4",
     "mermaid": "^11.4.1"
   },