Remove reduntant issue templates

## Overview
The [new-event](https://github.com/ACCESS-NRI/access-hive.org.au/blob/development/.github/ISSUE_TEMPLATE/new-event.yml) and [new-resource](https://github.com/ACCESS-NRI/access-hive.org.au/blob/development/.github/ISSUE_TEMPLATE/new-resource.yml) are redundant and should be removed.