Bump dotenv from 16.3.1 to 16.4.5 in /backend

Bumps [dotenv](https://github.com/motdotla/dotenv) from 16.3.1 to 16.4.5.
- [Changelog](https://github.com/motdotla/dotenv/blob/master/CHANGELOG.md)
- [Commits](motdotla/dotenv@v16.3.1...v16.4.5)

---
updated-dependencies:
- dependency-name: dotenv
  dependency-type: direct:production
  update-type: version-update:semver-minor
...

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

backend/package.json

@@ -40,7 +40,7 @@
     "@prisma/client": "^5.10.2",
     "@vuepress/theme-default": "^2.0.0-rc.17",
     "class-validator": "^0.14.0",
-    "dotenv": "^16.3.1",
+    "dotenv": "^16.4.5",
     "graphql": "^16.8.1",
     "graphql-scalars": "^1.22.5",
     "prisma": "^5.10.2",