chore: adjust renovate config [DX-665] (#1585)

## Summary

Tune Renovate config to widen the schedule window and pin
Node.js-related dependency updates to 18.x, matching the tool's
supported runtime (DX-665).

## Description

- Widen the Renovate schedule from `before 1am` to `before 5am` UTC,
giving Renovate a larger window to open PRs
- Change the `node` and `@types/node` version constraint from `<= 24` to
`^18`, preventing Renovate from proposing Node.js runtime or
type-definition bumps beyond the 18.x line
- Update the package rule description to reflect the new intent

## Motivation and Context

Keep the tool consistent with supporting Node 18+. The previous `<= 24`
cap allowed Renovate to create PRs upgrading the Node.js runtime to v24
and `@types/node` beyond the supported range. Pinning to `^18` ensures
only 18.x patch updates are proposed. Note that @types/node package is
on 20. Like previously, bumping node higher than 18 will be done
manually.

The schedule change increases on the previous 1-hour window, which was
tight. 5-hour window will allow renovate to run more reliably.

## PR Checklist

- [x] I have read the `CONTRIBUTING.md` file
- [x] All commits follow [conventional
commits](https://www.conventionalcommits.org/en/v1.0.0/)
- [x] Documentation is updated (if necessary)
- [x] PR doesn't contain any sensitive information
- [x] There are no breaking changes

Author: michaelphamcf

renovate.json

@@ -6,7 +6,7 @@
     ":automergeAll"
   ],
   "timezone": "UTC",
-  "schedule": ["before 1am"],
+  "schedule": ["before 5am"],
   "prConcurrentLimit": 15,
   "semanticCommits": "enabled",
   "semanticCommitType": "build",
@@ -38,9 +38,9 @@
       "groupName": "github-actions"
     },
     {
-      "description": "Cap Node.js to LTS and require manual approval",
+      "description": "Pin Node.js and @types/node to 18.x",
       "matchPackageNames": ["node", "@types/node"],
-      "allowedVersions": "<= 24",
+      "allowedVersions": "^18",
       "automerge": false
     }
   ]