fix: backend/package.json & backend/package-lock.json to reduce vulnerabilities (#309)

The following vulnerabilities are fixed with an upgrade:
- https://snyk.io/vuln/SNYK-JS-FORMDATA-10841150

Co-authored-by: snyk-bot <snyk-bot@snyk.io>

Author: lholmquist

backend/package-lock.json

@@ -24,7 +24,7 @@
     "mocha": "^11.7.1",
     "mongodb-memory-server": "^10.1.3",
     "nyc": "^17.0.0",
-    "supertest": "^7.1.1"
+    "supertest": "^7.1.3"
   },
   "support": true
 }