core: update to mongodb5 (#514)

packages/hydrojudge/package.json

@@ -9,7 +9,7 @@
         "@hydrooj/utils": "workspace:*",
         "cac": "^6.7.14",
         "fs-extra": "^11.1.0",
-        "mongodb": "^3.7.3",
+        "mongodb": "^5.1.0",
         "p-queue": "^7.3.4",
         "schemastery": "^3.7.1",
         "shell-quote": "^1.8.0",