chore(deps): bump helmet from 3.23.2 to 4.0.0

Bumps [helmet](https://github.com/helmetjs/helmet) from 3.23.2 to 4.0.0.
- [Release notes](https://github.com/helmetjs/helmet/releases)
- [Changelog](https://github.com/helmetjs/helmet/blob/master/CHANGELOG.md)
- [Commits](https://github.com/helmetjs/helmet/compare/v3.23.2...v4.0.0)

Signed-off-by: dependabot-preview[bot] <support@dependabot.com>

plugins/auth-backend/package.json

@@ -31,7 +31,7 @@
     "express": "^4.17.1",
     "express-promise-router": "^3.0.3",
     "fs-extra": "^9.0.0",
-    "helmet": "^3.22.0",
+    "helmet": "^4.0.0",
     "jose": "^1.27.1",
     "jwt-decode": "2.2.0",
     "knex": "^0.21.1",