Bump gatsby-plugin-sitemap from 5.19.0 to 5.25.0

Bumps [gatsby-plugin-sitemap](https://github.com/gatsbyjs/gatsby/tree/HEAD/packages/gatsby-plugin-sitemap) from 5.19.0 to 5.25.0.
- [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/[email protected]/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] <[email protected]>

Author: dependabot[bot]

package-lock.json

@@ -57,7 +57,7 @@
     "gatsby-plugin-preload-fonts": "^3.24.0",
     "gatsby-plugin-robots-txt": "^1.7.1",
     "gatsby-plugin-sharp": "^4.19.0",
-    "gatsby-plugin-sitemap": "^5.19.0",
+    "gatsby-plugin-sitemap": "^5.25.0",
     "gatsby-plugin-styled-components": "^5.19.0",
     "gatsby-plugin-svgr": "^3.0.0-beta.0",
     "gatsby-redirect-from": "^0.5.0",