build(deps): bump axios in /services/backend in the production group

Bumps the production group in /services/backend with 1 update: [axios](https://github.com/axios/axios).


Updates `axios` from 1.19.0 to 1.20.0
- [Release notes](https://github.com/axios/axios/releases)
- [Changelog](https://github.com/axios/axios/blob/v1.x/CHANGELOG.md)
- [Commits](https://github.com/axios/axios/compare/v1.19.0...v1.20.0)

---
updated-dependencies:
- dependency-name: axios
  dependency-version: 1.20.0
  dependency-type: direct:production
  update-type: version-update:semver-minor
  dependency-group: production
...

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

services/backend/package.json

@@ -16,7 +16,7 @@
   "dependencies": {
     "@discordjs/voice": "^0.19.2",
     "@orpc/server": "1.15.0",
-    "axios": "^1.16.1",
+    "axios": "^1.20.0",
     "dotenv": "^17.4.2",
     "drizzle-orm": "^0.45.2",
     "express": "^5.2.1",