build(deps): bump gatsby-plugin-sitemap from 6.13.1 to 6.14.0 (#3213)

Bumps [gatsby-plugin-sitemap](https://github.com/gatsbyjs/gatsby/tree/HEAD/packages/gatsby-plugin-sitemap) from 6.13.1 to 6.14.0.
- [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@6.14.0/packages/gatsby-plugin-sitemap)

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

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Co-authored-by: dependabot[bot] <49699333+dependabot[bot]@users.noreply.github.com>

package.json

@@ -35,7 +35,7 @@
     "gatsby-plugin-react-svg": "^3.3.0",
     "gatsby-plugin-sass": "^6.14.0",
     "gatsby-plugin-sharp": "^5.14.0",
-    "gatsby-plugin-sitemap": "^6.13.1",
+    "gatsby-plugin-sitemap": "^6.14.0",
     "gatsby-remark-autolink-headers": "^6.14.0",
     "gatsby-remark-code-titles": "^1.1.0",
     "gatsby-remark-copy-linked-files": "^6.14.0",