Bump dotenv from 16.0.1 to 16.0.3 in /backend

Bumps [dotenv](https://github.com/motdotla/dotenv) from 16.0.1 to 16.0.3.
- [Release notes](https://github.com/motdotla/dotenv/releases)
- [Changelog](https://github.com/motdotla/dotenv/blob/master/CHANGELOG.md)
- [Commits](motdotla/dotenv@v16.0.1...v16.0.3)

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

Signed-off-by: dependabot[bot] <[email protected]>

Author: dependabot[bot]

backend/package-lock.json

@@ -14,7 +14,7 @@
   "license": "MIT",
   "dependencies": {
     "@codam/fast42": "^1.4.2",
-    "dotenv": "^16.0.1",
+    "dotenv": "^16.0.3",
     "express": "^4.18.1"
   },
   "devDependencies": {