Docs: StoriesOf API removal

[jonniebigodes]

Follows up on #24655

What I did

With this pull request, I've updated the wording about the removal of the storiesOf API, that's been deprecated for a while and has now been removed.

@ndelangen and @JReinhold, when you have a moment, can both of you take a look and let me know of any feedback you may have so that we can get this merged in and the documentation updated to reflect these changes? Additionally, I would like some input on the storiesOf.md file located in the code/lib/preview-api/docs directory, specifically if we should keep it or not. I've updated the wording to factor in the removal, but wanted to hear from both of you first so that we can follow through.

Checklist for Contributors

Testing

1. Follow the steps in the contributing instructions for this branch, docs_stories_of_updates.
2. Open the relevant documentation and verify the feature changes.

The changes in this PR are covered in the following automated tests:

• stories
• unit tests
• integration tests
• end-to-end tests

Manual testing

This section is mandatory for all contributions. If you believe no manual test is necessary, please state so explicitly. Thanks!

Documentation

• Add or update documentation reflecting your changes
• If you are deprecating/removing a feature, make sure to update
  MIGRATION.MD

Checklist for Maintainers

• When this PR is ready for testing, make sure to add ci:normal, ci:merged or ci:daily GH label to it to run a specific set of sandboxes. The particular set of sandboxes can be found in code/lib/cli/src/sandbox-templates.ts

• Make sure this PR contains one of the labels below:

  Available labels

  • bug: Internal changes that fixes incorrect behavior.
  • maintenance: User-facing maintenance tasks.
  • dependencies: Upgrading (sometimes downgrading) dependencies.
  • build: Internal-facing build tooling & test updates. Will not show up in release changelog.
  • cleanup: Minor cleanup style change. Will not show up in release changelog.
  • documentation: Documentation only changes. Will not show up in release changelog.
  • feature request: Introducing a new feature.
  • BREAKING CHANGE: Changes that break compatibility in some way with current major version.
  • other: Changes that don't fit in the above categories.

🦋 Canary release

This PR does not have a canary release associated. You can request a canary release of this pull request by mentioning the @storybookjs/core team here.

core team members can create a canary release here or locally with gh workflow run --repo storybookjs/storybook canary-release-pr.yml --field pr=<PR_NUMBER>

[JReinhold]

I think we should remove this file completely.

[jonniebigodes]

@JReinhold I can work with that. We'll need to make some tweaks here so that we don't forget about it and unlink it from other places.