Bump sitemap_generator from 6.1.1 to 6.1.2 (#8324)

* Bump sitemap_generator from 6.1.1 to 6.1.2

Bumps [sitemap_generator](https://github.com/kjvarga/sitemap_generator) from 6.1.1 to 6.1.2.
- [Release notes](https://github.com/kjvarga/sitemap_generator/releases)
- [Changelog](https://github.com/kjvarga/sitemap_generator/blob/master/CHANGES.md)
- [Commits](https://github.com/kjvarga/sitemap_generator/compare/v6.1.1...v6.1.2)

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

* Bump sitemap_generator from 6.1.1 to 6.1.2 (Update vendor/cache)

Co-authored-by: dependabot-preview[bot] <27856297+dependabot-preview[bot]@users.noreply.github.com>

Gemfile.lock

@@ -762,7 +762,7 @@ GEM
       json (>= 1.8, < 3)
       simplecov-html (~> 0.10.0)
     simplecov-html (0.10.2)
-    sitemap_generator (6.1.1)
+    sitemap_generator (6.1.2)
       builder (~> 3.0)
     slack-notifier (2.3.2)
     smart_properties (1.15.0)