fix(deps): update dependency cron to v4

Author: renovate[bot]

package-lock.json

@@ -56,7 +56,7 @@
   },
   "homepage": "https://github.com/toolisticon/ssl-hostinfo-prometheus-exporter",
   "dependencies": {
-    "cron": "^3.0.0",
+    "cron": "^4.0.0",
     "date-fns": "^2.29.3",
     "log4bro": "^3.18.0",
     "node-fetch": "^2.6.9",