build(deps-dev): bump stylelint-scss from 3.20.1 to 3.21.0

Bumps [stylelint-scss](https://github.com/kristerkari/stylelint-scss) from 3.20.1 to 3.21.0.
- [Release notes](https://github.com/kristerkari/stylelint-scss/releases)
- [Changelog](https://github.com/kristerkari/stylelint-scss/blob/master/CHANGELOG.md)
- [Commits](stylelint-scss/stylelint-scss@3.20.1...3.21.0)

---
updated-dependencies:
- dependency-name: stylelint-scss
  dependency-type: direct:development
  update-type: version-update:semver-minor
...

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

Author: dependabot[bot]

package-lock.json

@@ -98,7 +98,7 @@
     "stream-http": "^3.2.0",
     "stylelint": "^13.13.1",
     "stylelint-config-standard": "^22.0.0",
-    "stylelint-scss": "^3.20.1",
+    "stylelint-scss": "^3.21.0",
     "ts-node": "^10.2.1",
     "typescript": "^4.3.5"
   },