Bump postcss from 8.4.19 to 8.4.31 in /web_api/static

Bumps [postcss](https://github.com/postcss/postcss) from 8.4.19 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@8.4.19...8.4.31)

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

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

Author: dependabot[bot]

web_api/static/package-lock.json

@@ -4,7 +4,7 @@
   "description": "Frontend part of Osmose QA tool - Sprites",
   "main": "index.js",
   "devDependencies": {
-    "postcss": "^8.3.6",
+    "postcss": "^8.4.31",
     "postcss-cli": "^8.3.1",
     "postcss-sprites": "^4.2.1"
   },