Bump nodemailer from 6.10.1 to 7.0.11 in /backend

Bumps [nodemailer](https://github.com/nodemailer/nodemailer) from 6.10.1 to 7.0.11.
- [Release notes](https://github.com/nodemailer/nodemailer/releases)
- [Changelog](https://github.com/nodemailer/nodemailer/blob/master/CHANGELOG.md)
- [Commits](nodemailer/nodemailer@v6.10.1...v7.0.11)

---
updated-dependencies:
- dependency-name: nodemailer
  dependency-version: 7.0.11
  dependency-type: direct:production
...

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

Author: dependabot[bot]

backend/package.json

@@ -47,7 +47,7 @@
     "multer": "^1.4.2",
     "node-cron": "^3.0.3",
     "node-fetch": "^2.6.1",
-    "nodemailer": "^6.5.0",
+    "nodemailer": "^7.0.11",
     "@snaplet/seed": "^0.98.0",
     "pg": "^8.5.1",
     "reflect-metadata": "^0.1.13",