Bump linkify-it-py from 2.0.3 to 2.1.0 in /docs

Bumps [linkify-it-py](https://github.com/tsutsu3/linkify-it-py) from 2.0.3 to 2.1.0.
- [Release notes](https://github.com/tsutsu3/linkify-it-py/releases)
- [Changelog](https://github.com/tsutsu3/linkify-it-py/blob/main/CHANGELOG.md)
- [Commits](tsutsu3/linkify-it-py@v2.0.3...v2.1.0)

---
updated-dependencies:
- dependency-name: linkify-it-py
  dependency-version: 2.1.0
  dependency-type: direct:production
  update-type: version-update:semver-minor
...

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

Author: dependabot[bot]

docs/requirements.txt

@@ -1,7 +1,7 @@
 aiohttp==3.13.3
 autodoc-pydantic==2.2.0
 furo==2025.12.19
-linkify-it-py==2.0.3
+linkify-it-py==2.1.0
 matplotlib==3.10.8
 myst-nb==1.3.0
 sphinx==8.2.3