build(deps): bump the production group

Bumps the production group in /services/backend with 2 updates: [@orpc/server](https://github.com/middleapi/orpc/tree/HEAD/packages/server) and [dotenv](https://github.com/motdotla/dotenv).


Updates `@orpc/server` from 1.15.1 to 1.15.2
- [Release notes](https://github.com/middleapi/orpc/releases)
- [Commits](https://github.com/middleapi/orpc/commits/v1.15.2/packages/server)

Updates `dotenv` from 18.0.0 to 18.0.1
- [Changelog](https://github.com/motdotla/dotenv/blob/master/CHANGELOG.md)
- [Commits](https://github.com/motdotla/dotenv/compare/v18.0.0...v18.0.1)

---
updated-dependencies:
- dependency-name: "@orpc/server"
  dependency-version: 1.15.2
  dependency-type: direct:production
  update-type: version-update:semver-patch
  dependency-group: production
- dependency-name: dotenv
  dependency-version: 18.0.1
  dependency-type: direct:production
  update-type: version-update:semver-patch
  dependency-group: production
...

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

services/backend/package.json

@@ -21,9 +21,9 @@
   },
   "dependencies": {
     "@discordjs/voice": "^0.19.2",
-    "@orpc/server": "1.15.1",
+    "@orpc/server": "1.15.2",
     "axios": "^1.20.0",
-    "dotenv": "^18.0.0",
+    "dotenv": "^18.0.1",
     "drizzle-orm": "^0.45.2",
     "express": "^5.2.1",
     "helmet": "^8.1.0",