Bump @types/supertest from 2.0.12 to 2.0.15 in /api

Bumps [@types/supertest](https://github.com/DefinitelyTyped/DefinitelyTyped/tree/HEAD/types/supertest) from 2.0.12 to 2.0.15.
- [Release notes](https://github.com/DefinitelyTyped/DefinitelyTyped/releases)
- [Commits](https://github.com/DefinitelyTyped/DefinitelyTyped/commits/HEAD/types/supertest)

---
updated-dependencies:
- dependency-name: "@types/supertest"
  dependency-type: direct:development
  update-type: version-update:semver-patch
...

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

api/package.json

@@ -26,7 +26,7 @@
     "swagger-ui-express": "^4.6.3"
   },
   "devDependencies": {
-    "@types/supertest": "^2.0.12",
+    "@types/supertest": "^2.0.15",
     "c8": "^7.14.0",
     "chai": "^4.3.10",
     "eslint": "^8.52.0",