Update dependency express to v4.21.0

Author: renovate[bot]

bun.lockb

@@ -42,7 +42,7 @@
   "dependencies": {
     "body-parser": "1.20.3",
     "cors": "2.8.5",
-    "express": "4.20.0",
+    "express": "4.21.0",
     "lodash": "4.17.21",
     "mongodb": "^6.5.0",
     "morgan": "1.10.0",