Next.js: Add next/font/local declarations support

[MauricioRobayo]

Discussion: #24979 (reply in thread)

What I did

Add support for next/font/local declarations.

Checklist for Contributors

Testing

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

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

Manual testing

1. Add ascent-override: 500% to localRubikStorm local font on the code/frameworks/nextjs/template/stories_nextjs-default-js/Font.jsx file.

export const localRubikStorm = localFont({
  src: '/fonts/RubikStorm-Regular.ttf',
  variable: '--font-rubik-storm',
+ declarations: [{ prop: 'ascent-override', value: '500%' }],
});

2. Start the nexjs/default-js sandbox:

yarn task --task dev --template nextjs/default-js --start-from=sandbox

3. Got to the /story/stories-frameworks-nextjs-nextjs-default-js-font--with-class-name story and select the text for the local font, you should be able to see how the ascent for the font was modified:

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>

[valentinpalkovic]

Great job! Well done.
LGTM!