Fixes commit diff expansion

Fixes a bug where diff expansion on commits was incorrectly rendering the expanded
section of the diff. This was caused by an extra element added in for the old
rendering instead of just the rapid diffs rendering.

app/helpers/diff_helper.rb

@@ -72,7 +72,7 @@ def diff_match_line(old_pos, new_pos, text: '', view: :inline, bottom: false)
       spinner = render(Pajamas::SpinnerComponent.new(size: :sm, class: 'gl-display-none gl-text-align-right', data: { visible_when_loading: true }))
       expand_html = content_tag(:div, [expand_button, spinner].join.html_safe, data: { expand_wrapper: true })
     else
-      expand_html = content_tag(:div, '...', data: { visible_when_loading: false, **expand_data })
+      expand_html = '...'
     end
 
     if old_pos