chore(deps): update dependency @types/supertest to v6

Author: renovate[bot]

package.json

@@ -97,7 +97,7 @@
     "@kazupon/eslint-config": "^0.38.0",
     "@kazupon/prettier-config": "^0.1.1",
     "@types/node": "^24.10.0",
-    "@types/supertest": "^2.0.16",
+    "@types/supertest": "^6.0.0",
     "@vitest/coverage-v8": "catalog:vitest",
     "@vitest/eslint-plugin": "^1.4.1",
     "bumpp": "^9.11.1",