Fix welcome page design on CE

The width for the welcome page card wasn't set since the style
definition was in EE. Since the welcome page layout is also used for
other steps, the `margin: 0` set on the `container` div made the card
not aligned in the middle of the page.

app/assets/stylesheets/page_bundles/signup.scss

@@ -73,3 +73,7 @@
     text-decoration: none;
   }
 }
+
+.edit-profile {
+  max-width: 460px;
+}

app/views/layouts/welcome.html.haml

@@ -4,5 +4,5 @@
   %body.ui-indigo.gl-display-flex.vh-100
     = render "layouts/header/logo_with_title"
     = render "layouts/broadcast"
-    .container.d-flex.flex-grow-1.m-0
+    .container.gl-display-flex.gl-flex-grow-1
       = yield

app/views/registrations/welcome/show.html.haml

 - page_title _('Your profile')
+- add_page_specific_style 'page_bundles/signup'
 
 .row.gl-flex-grow-1
   .d-flex.gl-flex-direction-column.gl-align-items-center.gl-w-full.gl-p-5

changelogs/unreleased/nicolasdular-fix-welcome-page.yml

+---
+title: Fix welcome page alignment on CE
+merge_request: 53265
+author:
+type: fixed