Remove check boxes from bug/enhancement issue template (not release)

[planetf1]

Our issue templates for bug/enhancement have tickboxes to see whether the originator would like to work on it, and whether they've checked existing issues.

I propose changing this to questions/references in free text rather than a checkbox

Otherwise nearly every issue shows '1 of 2 tasks' or '1 of 1 tasks' done which I think is confusing.

An issue owner can add tasks to be done as they wish - and it can be very helpful to see progress relating to big pieces of work, but here it, in my view, adds no value and just results in noise.

[github-actions]

This issue has been automatically marked as stale because it has not had recent activity. It will be closed in 20 days if no further activity occurs. Thank you for your contributions.