chore(deps): bump mkdocs-material from 9.6.18 to 9.6.19 in /docs/_build

Bumps [mkdocs-material](https://github.com/squidfunk/mkdocs-material) from 9.6.18 to 9.6.19.
- [Release notes](https://github.com/squidfunk/mkdocs-material/releases)
- [Changelog](https://github.com/squidfunk/mkdocs-material/blob/master/CHANGELOG)
- [Commits](https://github.com/squidfunk/mkdocs-material/compare/9.6.18...9.6.19)

---
updated-dependencies:
- dependency-name: mkdocs-material
  dependency-version: 9.6.19
  dependency-type: direct:production
  update-type: version-update:semver-patch
...

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

docs/_build/requirements.txt

@@ -8,7 +8,7 @@ MarkupSafe==3.0.2
 mergedeep==1.3.4
 mkdocs==1.6.1
 mkdocs-exclude==1.0.2
-mkdocs-material==9.6.18
+mkdocs-material==9.6.19
 mkdocs-material-extensions==1.3.1
 packaging==25.0
 Pygments==2.19.2