Bump mkdocs-material from 9.6.19 to 9.6.20

Bumps [mkdocs-material](https://github.com/squidfunk/mkdocs-material) from 9.6.19 to 9.6.20.
- [Release notes](https://github.com/squidfunk/mkdocs-material/releases)
- [Changelog](https://github.com/squidfunk/mkdocs-material/blob/master/CHANGELOG)
- [Commits](squidfunk/mkdocs-material@9.6.19...9.6.20)

---
updated-dependencies:
- dependency-name: mkdocs-material
  dependency-version: 9.6.20
  dependency-type: direct:production
  update-type: version-update:semver-patch
...

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

Author: dependabot[bot]

requirements/docs.txt

@@ -236,9 +236,9 @@ mkdocs-get-deps==0.2.0 \
 mkdocs-git-revision-date-plugin==0.3.2 \
     --hash=sha256:2e67956cb01823dd2418e2833f3623dee8604cdf223bddd005fe36226a56f6ef
     # via -r requirements/docs.in
-mkdocs-material==9.6.19 \
-    --hash=sha256:7492d2ac81952a467ca8a10cac915d6ea5c22876932f44b5a0f4f8e7d68ac06f \
-    --hash=sha256:80e7b3f9acabfee9b1f68bd12c26e59c865b3d5bbfb505fd1344e970db02c4aa
+mkdocs-material==9.6.20 \
+    --hash=sha256:b8d8c8b0444c7c06dd984b55ba456ce731f0035c5a1533cc86793618eb1e6c82 \
+    --hash=sha256:e1f84d21ec5fb730673c4259b2e0d39f8d32a3fef613e3a8e7094b012d43e790
     # via -r requirements/docs.in
 mkdocs-material-extensions==1.3.1 \
     --hash=sha256:10c9511cea88f568257f960358a467d12b970e1f7b2c0e5fb2bb48cab1928443 \