chore(deps): bump shibuya from 2025.2.14 to 2025.2.20

Bumps [shibuya](https://github.com/lepture/shibuya) from 2025.2.14 to 2025.2.20.
- [Release notes](https://github.com/lepture/shibuya/releases)
- [Changelog](https://github.com/lepture/shibuya/blob/main/docs/changelog.rst)
- [Commits](https://github.com/lepture/shibuya/commits)

---
updated-dependencies:
- dependency-name: shibuya
  dependency-type: direct:production
  update-type: version-update:semver-patch
...

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

requirements.txt

@@ -2,7 +2,7 @@ minify-html==0.15.0
 myst-parser==4.0.1
 rcssmin==1.2.1
 rjsmin==1.2.4
-shibuya==2025.2.14
+shibuya==2025.2.20
 sphinx==8.2.0
 sphinx-contributors==0.2.7
 sphinx-copybutton==0.5.2