Update dependency express to ^4.21.1

Author: mend-for-github-com[bot]

package.json

@@ -14,7 +14,7 @@
     "connect-sqlite3": "^0.9.13",
     "cookie-parser": "^1.4.6",
     "dotenv": "^16.3.1",
-    "express": "^4.18.2",
+    "express": "^4.21.1",
     "express-session": "^1.17.3",
     "sqlite3": "^5.1.6"
   },