Deprecate config policy provider

[akashsinghal]

What would you like to be added?

Now that we have support for rego policy provider, we should deprecate config policy provider as it is very limited and not the encouraged way to manage policy in ratify moving forward. Policy language providers will be the future supported behavior including CEL support in the future.

I propose the following timeline:

• 1.2: we announce plans to deprecate the config policy provider. In this release, we will switch default helm chart, config.json, and samples to use the rego policy provider.
• 1.3 we remove all documentation for it. Add deprecate warning to headers of all files related to it
• 1.4 we remove implementation completely, remove e2e tests. Remove extra JSON policy config paths we have in executor.go

Anything else you would like to add?

No response

Are you willing to submit PRs to contribute to this feature?

• [ ] Yes, I am willing to implement it.

[luisdlp]

We should announce deprecation/hide it/make it invisible/remove docs during 1.x releases and implement removal at the 2.0 release

[luisdlp]

Create a comprehensive list of impacted resources/touchpoints we'll need to modify as part of the proposal.

[susanshi]

We have to continue supporting this until 2.0. Create 2.0 milestone and make deprecation announcement in current release.