Bump postcss from 8.5.5 to 8.5.6 in /pkg/sass-parser

Bumps [postcss](https://github.com/postcss/postcss) from 8.5.5 to 8.5.6.
- [Release notes](https://github.com/postcss/postcss/releases)
- [Changelog](https://github.com/postcss/postcss/blob/main/CHANGELOG.md)
- [Commits](postcss/postcss@8.5.5...8.5.6)

---
updated-dependencies:
- dependency-name: postcss
  dependency-version: 8.5.6
  dependency-type: direct:production
  update-type: version-update:semver-patch
...

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

Author: dependabot[bot]

pkg/sass-parser/package.json

@@ -31,7 +31,7 @@
     "test": "jest"
   },
   "dependencies": {
-    "postcss": "8.5.5",
+    "postcss": "8.5.6",
     "sass": "file:../../build/npm"
   },
   "devDependencies": {