AFAIK pagure API does not allow to delete forks using API. This would be useful in order to delete forks in a easiest way from CLI or as part of automated workflows from maintainers tools.
Metadata Update from @pingou: - Issue tagged with: RFE
Metadata Update from @ngompa: - Issue set to the milestone: 5.11
Metadata Update from @pingou: - Issue assigned to pingou
Commit f07f5fba fixes this issue