Bump moment from 2.29.2 to 2.29.4 in /frontend

Bumps [moment](https://github.com/moment/moment) from 2.29.2 to 2.29.4.
- [Release notes](https://github.com/moment/moment/releases)
- [Changelog](https://github.com/moment/moment/blob/develop/CHANGELOG.md)
- [Commits](moment/moment@2.29.2...2.29.4)

---
updated-dependencies:
- dependency-name: moment
  dependency-type: direct:production
...

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

Author: dependabot[bot]

frontend/package-lock.json

@@ -15,7 +15,7 @@
     "es6-promise": "^4.2.8",
     "marked": "^0.7.0",
     "material-design-icons-iconfont": "^4.0.5",
-    "moment": "^2.29.2",
+    "moment": "^2.29.4",
     "node-sass": "^6.0.1",
     "pdfvuer": "^1.7.5",
     "stylus": "^0.54.8",