build(deps): bump dotenv from 17.4.2 to 18.0.0 in /services/backend

Bumps [dotenv](https://github.com/motdotla/dotenv) from 17.4.2 to 18.0.0.
- [Changelog](https://github.com/motdotla/dotenv/blob/master/CHANGELOG.md)
- [Commits](https://github.com/motdotla/dotenv/compare/v17.4.2...v18.0.0)

---
updated-dependencies:
- dependency-name: dotenv
  dependency-version: 18.0.0
  dependency-type: direct:production
  update-type: version-update:semver-major
...

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

services/backend/package.json

@@ -23,7 +23,7 @@
     "@discordjs/voice": "^0.19.2",
     "@orpc/server": "1.15.1",
     "axios": "^1.20.0",
-    "dotenv": "^17.4.2",
+    "dotenv": "^18.0.0",
     "drizzle-orm": "^0.45.2",
     "express": "^5.2.1",
     "helmet": "^8.1.0",