Tracking issue to enable `rattler-build` in conda-forge

I would like work towards enabling `rattler-build` on conda-forge and the new recipe format in Q1 2024.

This is a tracking issue for the remaining tasks:

- [ ] Stabilize recipe format and "rendered" recipe format. For this we mainly use the CEP process:
- [ ] https://github.com/conda-incubator/ceps/pull/56
- [ ] https://github.com/conda-incubator/ceps/pull/57
- [ ] Write a CFEP (conda-forge enhancement proposal) outlining how the transition works and get it voted on
- [ ] Make conda-smithy aware of the new recipe format
- [ ] Make the bots aware of the new recipe format

Other notes and important items

- The bot depends on the jinja2 parsing and making changes to it in order to generate certain bot PRs, especially the ones related generating pinning migrations.
- We should not migrate any of our core services feedstocks until things are very stable.