Issue Summary

When users are removed from Jira, their saved Dashboards are sent to Trash. When this is done, the owner is stripped and set to 'None'. This causes two issues:

1. Admins are unable to permanently delete trashed Dashboards with owner set to "None"
2. Dashboards in this state can cause import errors on Jira On-Prem / Data Center

Steps to Reproduce

1. Assign Dashboard to user
   
2. Remove user from Jira
   
3. Shared Items > Dashboards > Trash
   
4. Attempts to delete Dashboard silently fail
   

Expected Results

Admins should be able to delete any record in Dashboard trash, regardless of 'Owner' value. 

Actual Results

Dashboard silently fails to delete. There are no exceptions in the UI are corresponding network logs. 

1. dashboard_delete.har

Workaround

1. Restore dashboard from trash
   1. Admin is 'assigned' as new owner
2. Move dashboard to trash
3. Permanently delete