Bump postcss-nesting from 12.1.5 to 13.0.0

Bumps [postcss-nesting](https://github.com/csstools/postcss-plugins/tree/HEAD/plugins/postcss-nesting) from 12.1.5 to 13.0.0.
- [Changelog](https://github.com/csstools/postcss-plugins/blob/main/plugins/postcss-nesting/CHANGELOG.md)
- [Commits](https://github.com/csstools/postcss-plugins/commits/HEAD/plugins/postcss-nesting)

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

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

package.json

@@ -41,7 +41,7 @@
     "esbuild": "^0.23.0",
     "eslint": "^8.57.0",
     "eslint-config-standard": "^17.1.0",
-    "postcss-nesting": "^12.1.1",
+    "postcss-nesting": "^13.0.0",
     "tap-spec": "^5.0.0",
     "typedoc": "^0.26.2",
     "typescript": "^5.4.4"