Bump postcss and artillery in /test/load (#3467)

Bumps [postcss](https://github.com/postcss/postcss) to 8.4.32 and updates ancestor dependency [artillery](https://github.com/artilleryio/artillery). These dependencies need to be updated together.


Updates `postcss` from 7.0.39 to 8.4.32
- [Release notes](https://github.com/postcss/postcss/releases)
- [Changelog](https://github.com/postcss/postcss/blob/main/CHANGELOG.md)
- [Commits](https://github.com/postcss/postcss/compare/7.0.39...8.4.32)

Updates `artillery` from 2.0.0-36-f351294 to 2.0.2
- [Release notes](https://github.com/artilleryio/artillery/releases)
- [Commits](https://github.com/artilleryio/artillery/commits/artillery-2.0.2)

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

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Co-authored-by: dependabot[bot] <49699333+dependabot[bot]@users.noreply.github.com>

test/load/package.json

@@ -9,7 +9,7 @@
   "author": "",
   "license": "ISC",
   "dependencies": {
-    "artillery": "^2.0.0-36-f351294",
+    "artillery": "^2.0.2",
     "ws": "^7.4.6"
   }
 }