[web] Migrate post-gateway.pug to BS5 (#25860)

* Remove `data-ol-auto-submit`, to test the page

* Migrate post-gateway.pug to BS5

* Revert "Remove `data-ol-auto-submit`, to test the page"

This reverts commit ee728b0bdda80d739bd09b2e4e9419303f7053db.

* Fix breakbpoints

* Use `layout-marketing`

GitOrigin-RevId: 73aa4da1e4ddae03d9c8e6671c6a8ccb89ecf0b0

services/web/app/views/general/post-gateway.pug

@@ -5,15 +5,15 @@ block vars
 	- var suppressFooter = true
 	- var suppressSkipToContent = true
 	- var suppressCookieBanner = true
-	- bootstrap5PageStatus = 'disabled'
 
 block content
 	.content.content-alt
 		.container
 			.row
-				.col-md-6.col-md-offset-3
+				.col-lg-6.offset-lg-3
 					.card
-						p.text-center #{translate('processing_your_request')}
+						.card-body
+							p.text-center #{translate('processing_your_request')}
 
 	form(
 		data-ol-regular-form