Bump shibuya from 2025.2.28 to 2025.9.25

Bumps [shibuya](https://github.com/lepture/shibuya) from 2025.2.28 to 2025.9.25.
- [Release notes](https://github.com/lepture/shibuya/releases)
- [Changelog](https://github.com/lepture/shibuya/blob/main/docs/changelog.rst)
- [Commits](lepture/shibuya@2025.2.28...2025.9.25)

---
updated-dependencies:
- dependency-name: shibuya
  dependency-version: 2025.9.25
  dependency-type: direct:production
  update-type: version-update:semver-minor
...

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

Author: dependabot[bot]

pyproject.toml

@@ -12,7 +12,7 @@ dependencies = [
     "libgravatar==1.0.4",
     "matplotlib>=3.10.1",
     "myst-parser[linkify]==4.0.1",
-    "shibuya==2025.2.28",
+    "shibuya==2025.9.25",
     "sphinx==7.2.6",
     "sphinx-copybutton==0.5.2",
     "sphinx-design==0.5.0",