Remove deprecated activation batch scripts

[kenodegard]

Checklist

• I added a descriptive title
• I searched open requests and couldn't find a duplicate

What is the idea?

Review and deprecate all unused batch activation scripts.

Why is this needed?

Conda ships various batch scripts that have at various times been the de facto activation method. Most of these alternative activation methods are not recommended nor necessarily documented and instead exist solely to continue supporting various downstream tooling (e.g. Anaconda Prompt and Navigator) that at one point adopted the activation method in question and subsequently did not update to the newer methods as they became available.

Continuing to support all of these different activation methods is complex and time consuming and offers little benefit.

What should happen?

• Make an effort to understand what downstream tools are depending on which of these scripts
• Deprecate all but the necessary activation batch scripts
• Notify downstream tooling that the activation method they depend on is outdated and pending deprecation
• Hotfix repodata (probably both defaults and conda-forge) inserting an upper conda bound for these downstream tools

Additional Context

No response