Manager: fix panic on task timeout

Fix an issue where a timed-out task would cause a panic, as it wasn't
fetching its Job UUID.

I see this as working around a limitation of GORM, which should get
replaced with sqlc soon-ish anyway.

internal/manager/persistence/timeout.go

@@ -37,6 +37,15 @@ func (db *DB) FetchTimedOutTasks(ctx context.Context, untouchedSince time.Time)
 	if tx.Error != nil {
 		return nil, taskError(tx.Error, "finding timed out tasks (untouched since %s)", untouchedSince.String())
 	}
+
+	// GORM apparently doesn't call the task's AfterFind() function for the above query.
+	for _, task := range result {
+		err := task.AfterFind(tx)
+		if err != nil {
+			return nil, taskError(tx.Error, "finding the job & worker UUIDs for task %s", task.UUID)
+		}
+	}
+
 	return result, nil
 }