build(deps): bump @astrojs/sitemap from 3.7.2 to 3.7.3 in /website (#5284)

Bumps [@astrojs/sitemap](https://github.com/withastro/astro/tree/HEAD/packages/integrations/sitemap) from 3.7.2 to 3.7.3.
- [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@3.7.3/packages/integrations/sitemap)

---
updated-dependencies:
- dependency-name: "@astrojs/sitemap"
  dependency-version: 3.7.3
  dependency-type: direct:production
  update-type: version-update:semver-patch
...

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website/package-lock.json

@@ -16,7 +16,7 @@
     "@astrojs/mdx": "^5.0.6",
     "@astrojs/react": "^5.0.5",
     "@astrojs/rss": "^4.0.18",
-    "@astrojs/sitemap": "^3.7.2",
+    "@astrojs/sitemap": "^3.7.3",
     "@codesandbox/sandpack-react": "^2.20.0",
     "@docsearch/css": "^4.6.3",
     "@docsearch/js": "^4.6.3",