chore(deps-dev): bump vuepress-plugin-sitemap2

Bumps [vuepress-plugin-sitemap2](https://github.com/vuepress-theme-hope/vuepress-theme-hope/tree/HEAD/packages/sitemap2) from 2.0.0-beta.170 to 2.0.0-beta.172.
- [Release notes](https://github.com/vuepress-theme-hope/vuepress-theme-hope/releases)
- [Changelog](https://github.com/vuepress-theme-hope/vuepress-theme-hope/blob/main/CHANGELOG.md)
- [Commits](https://github.com/vuepress-theme-hope/vuepress-theme-hope/commits/v2.0.0-beta.172/packages/sitemap2)

---
updated-dependencies:
- dependency-name: vuepress-plugin-sitemap2
  dependency-type: direct:development
  update-type: version-update:semver-patch
...

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