chore(backend): bump @commitlint/config-conventional

Bumps [@commitlint/config-conventional](https://github.com/conventional-changelog/commitlint/tree/HEAD/@commitlint/config-conventional) from 20.5.3 to 21.0.0.
- [Release notes](https://github.com/conventional-changelog/commitlint/releases)
- [Changelog](https://github.com/conventional-changelog/commitlint/blob/master/@commitlint/config-conventional/CHANGELOG.md)
- [Commits](https://github.com/conventional-changelog/commitlint/commits/v21.0.0/@commitlint/config-conventional)

---
updated-dependencies:
- dependency-name: "@commitlint/config-conventional"
  dependency-version: 21.0.0
  dependency-type: direct:development
  update-type: version-update:semver-major
...

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

Author: dependabot[bot]

services/backend/package.json

@@ -53,7 +53,7 @@
   },
   "devDependencies": {
     "@commitlint/cli": "^20.4.3",
-    "@commitlint/config-conventional": "^20.4.1",
+    "@commitlint/config-conventional": "^21.0.0",
     "@eslint/js": "^10.0.1",
     "@release-it/conventional-changelog": "^10.0.5",
     "@types/fs-extra": "^11.0.4",