Bump @astrojs/sitemap from 3.1.4 to 3.1.6

Bumps [@astrojs/sitemap](https://github.com/withastro/astro/tree/HEAD/packages/integrations/sitemap) from 3.1.4 to 3.1.6.
- [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@3.1.6/packages/integrations/sitemap)

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

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

Author: dependabot[bot]

package-lock.json

@@ -15,7 +15,7 @@
     "@astrojs/mdx": "^3.1.0",
     "@astrojs/netlify": "^5.3.0",
     "@astrojs/rss": "^4.0.6",
-    "@astrojs/sitemap": "^3.1.4",
+    "@astrojs/sitemap": "^3.1.6",
     "@astrojs/svelte": "^5.4.0",
     "@astrojs/tailwind": "^5.1.0",
     "@codemirror/commands": "^6.5.0",