Update epic cache counts when an issue is deleted
Related to #378907 (comment 1234308607)
When an issue is deleted, it doesn't update cache counts of associated epic (if there is any). We should enqueue cache count update in this case.
Related to #378907 (comment 1234308607)
When an issue is deleted, it doesn't update cache counts of associated epic (if there is any). We should enqueue cache count update in this case.