chore(deps): bump squidfunk/mkdocs-material in /docs

Bumps squidfunk/mkdocs-material from `33e28bd` to `db16d8c`.

---
updated-dependencies:
- dependency-name: squidfunk/mkdocs-material
  dependency-type: direct:production
...

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

docs/Dockerfile

@@ -1,5 +1,5 @@
 # v9.1.18
-FROM squidfunk/mkdocs-material@sha256:33e28bdae302bc1aa9c6783dd863742416cb1174bae4ad9d7bcc5b2efe685639
+FROM squidfunk/mkdocs-material@sha256:db16d8c9433c94ee20c0310c2758952f3110d69c99fa61de8cb1b583badce8cc
 # pip-compile --generate-hashes --output-file=requirements.txt requirements.in
 COPY requirements.txt /tmp/
 RUN pip install --require-hashes -r /tmp/requirements.txt