3953 move plone app registry to plone app layout

[faro76]

• I signed and returned the Plone Contributor Agreement, and received and accepted an invitation to join a team in the Plone GitHub organization.
• I verified there aren't any other open pull requests for the same change.
• I followed the guidelines in Contributing to Plone.
• I successfully ran code quality checks on my changes locally.
• I successfully ran tests on my changes locally.
• If needed, I added new tests for my changes.
• If needed, I added documentation for my changes.
• I included a change log entry in my commits.

Test together on Jenkins:

https://github.com/plone/plone.app.registry/pull/113
https://github.com/plone/plone.app.layout/pull/437

[mister-roboto]

@faro76 thanks for creating this Pull Request and helping to improve Plone!

TL;DR: Finish pushing changes, pass all other checks, then paste a comment:

@jenkins-plone-org please run jobs

To ensure that these changes do not break other parts of Plone, the Plone test suite matrix needs to pass, but it takes 30-60 min. Other CI checks are usually much faster and the Plone Jenkins resources are limited, so when done pushing changes and all other checks pass either start all Jenkins PR jobs yourself, or simply add the comment above in this PR to start all the jobs automatically.

Happy hacking!

[ale-rt]

Please add a towncrier entry, e.g.:

uvx towncrier create

We also need to make a branch for 6.2 only and make this 6.3 compatible only.
Then we can run:

uvx --from plone.meta config-package .

And make this package tested on 6.3 only.