Bump sass from 1.74.1 to 1.75.0 in /src/sphinx_antsibull_ext/css (#272)

Bumps [sass](https://github.com/sass/dart-sass) from 1.74.1 to 1.75.0.
- [Release notes](https://github.com/sass/dart-sass/releases)
- [Changelog](https://github.com/sass/dart-sass/blob/main/CHANGELOG.md)
- [Commits](sass/dart-sass@1.74.1...1.75.0)

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

Signed-off-by: dependabot[bot] <support@github.com>
Co-authored-by: dependabot[bot] <49699333+dependabot[bot]@users.noreply.github.com>

src/sphinx_antsibull_ext/css/package.json

@@ -4,6 +4,6 @@
     "cssnano": "^6.1.2",
     "postcss": "^8.4.38",
     "postcss-cli": "^11.0.0",
-    "sass": "^1.74.1"
+    "sass": "^1.75.0"
   }
 }