Remove .issue-box element from Epics (list)

This is a single-line change.
Signed-off-by: Takuya Noguchi <takninnovationresearch@gmail.com>

ee/app/views/groups/epics/_epic.html.haml

 %li{ id: dom_id(epic), data: { labels: epic.label_ids, id: epic.id } }
-  .issue-box
+  .issuable-info-container
     - if @can_bulk_update
       .issue-check.hidden
         = check_box_tag dom_id(epic, "selected"), nil, false, 'data-id' => epic.id, class: "selected-issuable"
-    .issuable-info-container
     .issuable-main-info
       .issue-title.title
         %span.issue-title-text{ data: { qa_selector: 'epic_title_text' } }

ee/changelogs/unreleased/284602-remove-issue-box-epic.yml

+---
+title: Remove .issue-box element from Epics (list)
+merge_request: 48000
+author: Takuya Noguchi
+type: performance