chore(docs): bump mkdocs-material

Bumps the python-deps group in /.github/workflows/mkdocs with 1 update: [mkdocs-material](https://github.com/squidfunk/mkdocs-material).


Updates `mkdocs-material` from 9.6.20 to 9.6.21
- [Release notes](https://github.com/squidfunk/mkdocs-material/releases)
- [Changelog](https://github.com/squidfunk/mkdocs-material/blob/master/CHANGELOG)
- [Commits](squidfunk/mkdocs-material@9.6.20...9.6.21)

---
updated-dependencies:
- dependency-name: mkdocs-material
  dependency-version: 9.6.21
  dependency-type: direct:production
  update-type: version-update:semver-patch
  dependency-group: python-deps
...

Signed-off-by: dependabot[bot] <[email protected]>

Author: dependabot[bot]

.github/workflows/mkdocs/requirements.in

@@ -1 +1 @@
-mkdocs-material==9.6.20
+mkdocs-material==9.6.21

.github/workflows/mkdocs/requirements.txt

@@ -118,9 +118,7 @@ charset-normalizer==3.4.2 \
 click==8.2.1 \
     --hash=sha256:27c491cc05d968d271d5a1db13e3b5a184636d9d930f148c50b038f0d0646202 \
     --hash=sha256:61a3265b914e850b85317d0b3109c7f8cd35a670f963866005d6ef1d5175a12b
-    # via
-    #   mkdocs
-    #   mkdocs-material
+    # via mkdocs
 colorama==0.4.6 \
     --hash=sha256:08695f5cb7ed6e0531a20572697297273c47b8cae5a63ffc6d6ed5c201be6e44 \
     --hash=sha256:4f1d9991f5acc0ca119f9d443620b77f9d6b33703e51011c16baf57afb285fc6
@@ -225,9 +223,9 @@ mkdocs-get-deps==0.2.0 \
     --hash=sha256:162b3d129c7fad9b19abfdcb9c1458a651628e4b1dea628ac68790fb3061c60c \
     --hash=sha256:2bf11d0b133e77a0dd036abeeb06dec8775e46efa526dc70667d8863eefc6134
     # via mkdocs
-mkdocs-material==9.6.20 \
-    --hash=sha256:b8d8c8b0444c7c06dd984b55ba456ce731f0035c5a1533cc86793618eb1e6c82 \
-    --hash=sha256:e1f84d21ec5fb730673c4259b2e0d39f8d32a3fef613e3a8e7094b012d43e790
+mkdocs-material==9.6.21 \
+    --hash=sha256:aa6a5ab6fb4f6d381588ac51da8782a4d3757cb3d1b174f81a2ec126e1f22c92 \
+    --hash=sha256:b01aa6d2731322438056f360f0e623d3faae981f8f2d8c68b1b973f4f2657870
     # via -r requirements.in
 mkdocs-material-extensions==1.3.1 \
     --hash=sha256:10c9511cea88f568257f960358a467d12b970e1f7b2c0e5fb2bb48cab1928443 \