build(deps): bump gatsby-plugin-sitemap in /packages/website

Bumps [gatsby-plugin-sitemap](https://github.com/gatsbyjs/gatsby/tree/HEAD/packages/gatsby-plugin-sitemap) from 5.7.0 to 5.8.0.
- [Release notes](https://github.com/gatsbyjs/gatsby/releases)
- [Changelog](https://github.com/gatsbyjs/gatsby/blob/master/packages/gatsby-plugin-sitemap/CHANGELOG.md)
- [Commits](https://github.com/gatsbyjs/gatsby/commits/gatsby-plugin-sitemap@5.8.0/packages/gatsby-plugin-sitemap)

---
updated-dependencies:
- dependency-name: gatsby-plugin-sitemap
  dependency-type: direct:production
  update-type: version-update:semver-minor
...

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

packages/website/package.json

@@ -24,7 +24,7 @@
     "gatsby-plugin-react-helmet": "5.7.0",
     "gatsby-plugin-robots-txt": "1.7.0",
     "gatsby-plugin-sharp": "4.8.1",
-    "gatsby-plugin-sitemap": "5.7.0",
+    "gatsby-plugin-sitemap": "5.8.0",
     "gatsby-plugin-svgr": "3.0.0-beta.0",
     "gatsby-remark-classes": "1.0.2",
     "gatsby-remark-copy-linked-files": "5.7.0",

packages/website/yarn.lock

@@ -6052,10 +6052,10 @@ gatsby-plugin-sharp@4.8.1:
     svgo "1.3.2"
     uuid "3.4.0"
 
-gatsby-plugin-sitemap@5.7.0:
-  version "5.7.0"
-  resolved "https://registry.yarnpkg.com/gatsby-plugin-sitemap/-/gatsby-plugin-sitemap-5.7.0.tgz#87ab72f9acfac31dcd8f25ad0fb6afe5a2c221fa"
-  integrity sha512-53l+SXOHYp2Bt/8sK0DfLRjGq+K63qQGAPJksv1qC3soDNNe+TlKxmzM7JksACLzDVUkFVQYrvmS2RvMfivqeA==
+gatsby-plugin-sitemap@5.8.0:
+  version "5.8.0"
+  resolved "https://registry.yarnpkg.com/gatsby-plugin-sitemap/-/gatsby-plugin-sitemap-5.8.0.tgz#102430910cc5d7f57fc9bd84f9811780215fe283"
+  integrity sha512-RjWXnAVtAnFvltuoDW85d8JnxYrx48vLK0eiPnmgD1JwLTrH/64/kN6KaUC9oWopp2SgeCasXEIGiTpkhRTefw==
   dependencies:
     "@babel/runtime" "^7.15.4"
     common-tags "^1.8.2"