Update changelog.json

Author: gfletcher-cll

public/changelog.json

@@ -373,6 +373,13 @@
       "title": "CCIP Expands to Tempo Testnet",
       "topic": "CCIP"
     },
+    {
+      "category": "release",
+      "date": "2025-12-11",
+      "description": "Upgraded Time-based Upkeeps. Read more [here](https://docs.chain.link/chainlink-automation/guides/job-scheduler)",
+      "title": "Upgraded Time-based Upkeeps ",
+      "topic": "Automation"
+    },
     {
       "category": "integration",
       "date": "2025-12-09",