Remove the unused renovate.json5 file (#3489)

Signed-off-by: Miki <miki@amazon.com>

Author: AMoo-Miki

CHANGELOG.md

@@ -138,6 +138,7 @@ Inspired from [Keep a Changelog](https://keepachangelog.com/en/1.0.0/)
 - Allow relaxing the Node.js runtime version requirement ([3402](https://github.com/opensearch-project/OpenSearch-Dashboards/pull/3402))
 - Relax the Node.js requirement to `^14.20.1` ([3463](https://github.com/opensearch-project/OpenSearch-Dashboards/pull/3463))
 - Bump the version of Node.js installed by `nvm` to `14.21.3` ([3463](https://github.com/opensearch-project/OpenSearch-Dashboards/pull/3463))
+- Remove the unused `renovate.json5` file ([3489](https://github.com/opensearch-project/OpenSearch-Dashboards/pull/3489))
 
 ### 🪛 Refactoring