build(deps-dev): bump postcss-advanced-variables from 3.0.1 to 4.0.0

Bumps [postcss-advanced-variables](https://github.com/jonathantneal/postcss-advanced-variables) from 3.0.1 to 4.0.0.
- [Changelog](https://github.com/csstools/postcss-advanced-variables/blob/main/CHANGELOG.md)
- [Commits](https://github.com/jonathantneal/postcss-advanced-variables/commits)

---
updated-dependencies:
- dependency-name: postcss-advanced-variables
  dependency-type: direct:development
  update-type: version-update:semver-major
...

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

Author: dependabot[bot]

package-lock.json

@@ -102,7 +102,7 @@
     "npm-check-updates": "16.10.16",
     "plop": "3.1.2",
     "postcss": "8.4.36",
-    "postcss-advanced-variables": "3.0.1",
+    "postcss-advanced-variables": "4.0.0",
     "postcss-cli": "11.0.0",
     "postcss-color-function": "4.1.0",
     "postcss-custom-properties": "13.3.4",