fix: #3637883 The page layouts print the page title in a span, so no page has an h1

Issue: https://www.drupal.org/node/3637883

The eleven page layouts placed the page title source straight in their main section. Display Builder 1.0.0-beta10 prints that source as the title text only, in a <span> (upstream #3621589), so no page had an h1, the front page included. The layouts now put the title in the Heading component (ui_suite_uikit:heading), level 1, as Webship Starter does, and composer.json conflicts with the Display Builder releases before 1.0.0-beta10, whose page title prints an h1 of its own. The recipe job counts one h1 on /, /about-us and /welcome, and the accessibility feature checks a blog post, the UIkit showcase, the documentation and the page not found page.

Proof: on a Website 12.0.x site installed from this branch, curl -sk https://<site>/about-us | grep -c '<h1' gives 1 on /, /about-us and /blog/getting-started-uikit (0 on each with 1.0.8).

Not part of this change: /form/contact now prints its h1 and then an h3, so "the heading hierarchy should be valid" fails there, which the missing h1 hid.

AI-Generated: Yes

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