Create issues in configured issue_repository for Github via regular token
When Packit Service creates issues for downstream job failures (specifically for koji-build and bodhi-update) and the issue_repository configured by the user is hosted in GitHub, we currently use the authentication via application installation (by default), so the issue_repository needs to have Packit Github app installed. It would be nice if this is not the requirement.
Since using other authentication methods is now possible (see https://github.com/packit/ogr/pull/767), we could use the regular token for creating these issues.
This already works for pull-from-upstream (see #1902). The only thing that could be misleading is that retriggering of koji-build and bodhi-updates via comments in the issues in issue_repository would still require Packit Github app installed since we need to receive events about the comments.
Still relevant, low priority.