[EZ][BE] Delete ISSUE_TEMPALTE.md (pytorch#137040)

As it has been superseded by [ISSUES_TEMPLATE](https://github.com/pytorch/pytorch/tree/main/.github/ISSUE_TEMPLATE) folder, per https://docs.github.com/en/communities/using-templates-to-encourage-useful-issues-and-pull-requests/configuring-issue-templates-for-your-repository#creating-issue-forms

Pull Request resolved: pytorch#137040
Approved by: https://github.com/ZainRizvi