Bump sphinx-sitemap from 2.5.1 to 2.6.0

Bumps [sphinx-sitemap](https://github.com/jdillard/sphinx-sitemap) from 2.5.1 to 2.6.0.
- [Release notes](https://github.com/jdillard/sphinx-sitemap/releases)
- [Changelog](https://github.com/jdillard/sphinx-sitemap/blob/master/CHANGELOG.rst)
- [Commits](jdillard/sphinx-sitemap@v2.5.1...v2.6.0)

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

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

requirements/docs.txt

@@ -7,7 +7,7 @@ sphinx-copybutton==0.5.2
 sphinx-autobuild==2024.4.16
 sphinx-issues==4.1.0
 sphinxext-opengraph==0.9.1
-sphinx-sitemap==2.5.1
+sphinx-sitemap==2.6.0
 sphinx-paramlinks==0.6.0
 sphinxcontrib-programoutput==0.17