build(deps): 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](https://github.com/nodemailer/nodemailer/compare/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>

backend/package.json

@@ -23,7 +23,7 @@
     "dotenv": "^16.4.5",
     "drizzle-orm": "^0.32.2",
     "fastify": "^5.0.0",
-    "nodemailer": "^6.10.1",
+    "nodemailer": "^7.0.11",
     "openid-client": "^6.8.1",
     "zod": "^3.23.8"
   },