Revert "Merge branch 'pages-version-v1-13-0' into 'master'"

What does this MR do?

The new Pages version v1.13.0 is causing very long domain configuration times, see gitlab-com/gl-infra/delivery#633 (comment 272847098).

Last 12 hours:

Visualization can be found here - https://log.gitlab.net/app/kibana#/visualize/edit/AW1MeitpGphUgZwzuDHL?_g=(refreshInterval%3A(display%3AOff%2Cpause%3A!f%2Cvalue%3A0)%2Ctime%3A(from%3Anow-7d%2Cmode%3Aquick%2Cto%3Anow)).

This MR reverts !23023 (merged) and goes back to v1.12.0.

Screenshots

Does this MR meet the acceptance criteria?

Conformity

• Changelog entry
• Documentation (if required)
• Code review guidelines
• Merge request performance guidelines
• Style guides
• Database guides
• Separation of EE specific content

Availability and Testing

• Review and add/update tests for this feature/bug. Consider all test levels. See the Test Planning Process.
• Tested in all supported browsers

Security

If this MR contains changes to processing or storing of credentials or tokens, authorization and authentication methods and other items described in the security review guidelines:

• Label as security and @ mention @gitlab-com/gl-security/appsec
• The MR includes necessary changes to maintain consistency between UI, API, email, or other methods
• Security reports checked/validated by a reviewer from the AppSec team