chore: bump postcss from 8.4.30 to 8.4.31 (#9354)

Bumps [postcss](https://github.com/postcss/postcss) from 8.4.30 to 8.4.31.
- [Release notes](https://github.com/postcss/postcss/releases)
- [Changelog](https://github.com/postcss/postcss/blob/main/CHANGELOG.md)
- [Commits](postcss/postcss@8.4.30...8.4.31)

---
updated-dependencies:
- dependency-name: postcss
  dependency-type: direct:production
...

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packages/compiler-sfc/package.json

@@ -40,7 +40,7 @@
     "@vue/shared": "3.3.4",
     "estree-walker": "^2.0.2",
     "magic-string": "^0.30.5",
-    "postcss": "^8.4.30",
+    "postcss": "^8.4.31",
     "source-map-js": "^1.0.2"
   },
   "devDependencies": {