What type of PR is this? (Check one of the boxes below)

• Bug fix (non-breaking change which fixes an issue)

What does this pull request do?

It removes the old ISSUE_TEMPLATE.md file because it was meddling with the creation of issues in the GitHub CLI (gh) and probably the browser was affected by this.

Show a few screenshots (if this is a visual change)

N/A.

Have you tested your changes (if applicable)? If so, how?

By creating an issue in the GitHub CLI and selecting the proper template.

Futher details of this pull request

This may even fix #709 (?).