Bump @astrojs/sitemap from 3.1.5 to 3.1.6

Bumps [@astrojs/sitemap](https://github.com/withastro/astro/tree/HEAD/packages/integrations/sitemap) 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/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>

package.json

@@ -32,7 +32,7 @@
 	},
 	"dependencies": {
 		"@astrojs/prefetch": "0.4.1",
-		"@astrojs/sitemap": "3.1.5",
+		"@astrojs/sitemap": "3.1.6",
 		"@playform/build": "0.0.11",
 		"@playform/compress": "0.0.13",
 		"@playform/format": "0.0.5",