chore(deps): bump @adobe/css-tools from 4.2.0 to 4.3.1 (#2818)

Bumps [@adobe/css-tools](https://github.com/adobe/css-tools) from 4.2.0 to 4.3.1.
- [Changelog](https://github.com/adobe/css-tools/blob/main/History.md)
- [Commits](https://github.com/adobe/css-tools/commits)

---
updated-dependencies:
- dependency-name: "@adobe/css-tools"
  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>

package.json

@@ -28,7 +28,7 @@
     "test": "mocha test/ test/middleware/ --require chai --bail --check-leaks --reporter dot"
   },
   "dependencies": {
-    "@adobe/css-tools": "~4.2.0",
+    "@adobe/css-tools": "~4.3.1",
     "debug": "^4.3.2",
     "glob": "^7.1.6",
     "sax": "~1.3.0",