chore(deps-dev): bump @types/node from 22.19.15 to 26.1.2 in /backend

Bumps [@types/node](https://github.com/DefinitelyTyped/DefinitelyTyped/tree/HEAD/types/node) from 22.19.15 to 26.1.2.
- [Release notes](https://github.com/DefinitelyTyped/DefinitelyTyped/releases)
- [Commits](https://github.com/DefinitelyTyped/DefinitelyTyped/commits/HEAD/types/node)

---
updated-dependencies:
- dependency-name: "@types/node"
  dependency-version: 26.1.2
  dependency-type: direct:development
  update-type: version-update:semver-major
...

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

Author: dependabot[bot]

backend/package.json

@@ -78,7 +78,7 @@
     "@nestjs/cli": "^11.0.16",
     "@nestjs/testing": "^10.4.0",
     "@types/jest": "^29.5.14",
-    "@types/node": "^22.0.0",
+    "@types/node": "^26.1.2",
     "@types/passport-jwt": "^4.0.1",
     "@types/react": "^18.3.1",
     "@types/react-dom": "^18.3.1",