Add type=button to issue type selector to prevent premature submission

app/views/shared/issuable/form/_type_selector.html.haml

@@ -13,7 +13,7 @@
           .dropdown-title.gl-display-flex
             %span.gl-ml-auto
               = _("Select type")
-            %button.dropdown-title-button.dropdown-menu-close.gl-ml-auto{ "aria-label" => _('Close') }
+            %button.dropdown-title-button.dropdown-menu-close.gl-ml-auto{ type: 'button', "aria-label" => _('Close') }
               = sprite_icon('close', size: 16, css_class: 'dropdown-menu-close-icon')
           .dropdown-content
             %ul

changelogs/unreleased/273580-when-selecting-issue-type-and-closing-the-dropdown-the-issue-gets-.yml

+---
+title: Adds type="button" to the close button for the issue type selector to prevent
+  accidental form submission
+merge_request: 48249
+author:
+type: fixed