build(deps): bump markdown-it-py from 3.0.0 to 4.0.0 in /docs

Bumps [markdown-it-py](https://github.com/executablebooks/markdown-it-py) from 3.0.0 to 4.0.0.
- [Release notes](https://github.com/executablebooks/markdown-it-py/releases)
- [Changelog](https://github.com/executablebooks/markdown-it-py/blob/master/CHANGELOG.md)
- [Commits](executablebooks/markdown-it-py@v3.0.0...v4.0.0)

---
updated-dependencies:
- dependency-name: markdown-it-py
  dependency-version: 4.0.0
  dependency-type: direct:production
  update-type: version-update:semver-major
...

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

Author: dependabot[bot]

docs/requirements.txt

@@ -137,9 +137,9 @@ jinja2==3.1.6 \
     #   myst-parser
     #   readthedocs-sphinx-ext
     #   sphinx
-markdown-it-py==3.0.0 \
-    --hash=sha256:355216845c60bd96232cd8d8c40e8f9765cc86f46880e43a8fd22dc1a1a8cab1 \
-    --hash=sha256:e3f60a94fa066dc52ec76661e37c851cb232d92f9886b15cb560aaada2df8feb
+markdown-it-py==4.0.0 \
+    --hash=sha256:87327c59b172c5011896038353a81343b6754500a08cd7a4973bb48c6d578147 \
+    --hash=sha256:cb0a2b4aa34f932c007117b194e945bd74e0ec24133ceb5bac59009cda1cb9f3
     # via
     #   mdit-py-plugins
     #   myst-parser