Bump helmet from 4.6.0 to 7.1.0

Bumps [helmet](https://github.com/helmetjs/helmet) from 4.6.0 to 7.1.0.
- [Changelog](https://github.com/helmetjs/helmet/blob/main/CHANGELOG.md)
- [Commits](https://github.com/helmetjs/helmet/compare/v4.6.0...v7.1.0)

---
updated-dependencies:
- dependency-name: helmet
  dependency-type: direct:production
  update-type: version-update:semver-major
...

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

package.json

@@ -9,7 +9,7 @@
     "express": "^4.16.4",
     "formidable": "^1.2.1",
     "fs-extra": "^9.0.0",
-    "helmet": "^4.0.0",
+    "helmet": "^7.1.0",
     "lowdb": "^1.0.0",
     "path": "^0.12.7",
     "remarkable": "^2.0.0",