We added a check to "moveList" vuex action
which serves as the handler for list Draggables in
https://gitlab.com/gitlab-org/gitlab/-/merge_requests/68126.

The check ensured that only move events fired by
list Draggables were handled by "moveList" by checking
for data-draggable-item-type attribute.

The attribute's been missing for epic swimlane columns
breaking the drag and drop reordering of lists in
epic swimlanes.

This commit adds the attribute to epic swimlane columns

Changelog: fixed
EE: true