chore: remove unused dependencies

Remove 30 dependencies across 18 packages that have no imports in
source code and are not peer dependencies of any other dependency.

Signed-off-by: Fredrik Adelöw <freben@spotify.com>
Made-with: Cursor

plugins/techdocs-react/package.json

@@ -69,7 +69,6 @@
     "@material-ui/styles": "^4.11.0",
     "jss": "~10.10.0",
     "lodash": "^4.17.21",
-    "react-helmet": "6.1.0",
     "react-use": "^17.2.4"
   },
   "devDependencies": {