The email field of the registration form uses type text

The email field of the registration form declares autocomplete="email" but is still rendered with type="text", unlike the email field of the "Forgot your user name" form, which XWIKI-24838 switches to type="email".

With type="text", mobile browsers show a generic keyboard instead of the email one, and the browser's native email format validation is not applied.

Steps to reproduce

• Log out.
• Go to /xwiki/bin/register/XWiki/XWikiRegister.
• Inspect the email input.

Actual behaviour

The input has type="text" and autocomplete="email".

Expected behaviour

The input has type="email" and autocomplete="email", consistently with the "Forgot your user name" form.

Location

The register_email field definition in xwiki-platform-core/xwiki-platform-administration/xwiki-platform-administration-ui/src/main/resources/XWiki/Registration.xml. The field already has its own regex validation, so the change needs to check that the native validation does not conflict with it.