Add close button to group plan modal (#7959)

* add close button to group plan modal

* change hardcoded string to translation key

GitOrigin-RevId: fa259745cad1a6214d06a1379fc5c3ffb8377557

services/web/app/views/subscriptions/plans-marketing/_group_plan_modal.pug

@@ -6,6 +6,12 @@ div.modal.fade(tabindex="-1" role="dialog" data-ol-group-plan-modal)
 			event-tracking-trigger="load"
 		)
 			.modal-header
+				button.close(
+					type="button"
+					data-dismiss="modal"
+					aria-label=translate("close")
+				)
+					span(aria-hidden="true") ×
 				h2 Customise your group subscription
 				h3 Save 30% or more
 			.modal-body.plans.group-subscription-modal