Added eslint to ignored deps

ref https://linear.app/tryghost/issue/ENG-920/handle-eslint-v9-major-config-changes

- eslint v9 has a major / breaking config change
- we will need to manage this holistically across our repos
- for now, pin eslint, we can update to the latest v8 manually if we need to
- the linked issue has undoing this as a listed task

packages/renovate-config/package.json

@@ -34,6 +34,7 @@
         "yarnDedupeHighest"
       ],
       "ignoreDeps": [
+        "eslint",
         "moment",
         "moment-timezone"
       ]