⬆️ Bump @storybook/addon-actions from 6.2.9 to 6.4.21

Bumps [@storybook/addon-actions](https://github.com/storybookjs/storybook/tree/HEAD/addons/actions) from 6.2.9 to 6.4.21.
- [Release notes](https://github.com/storybookjs/storybook/releases)
- [Changelog](https://github.com/storybookjs/storybook/blob/next/CHANGELOG.md)
- [Commits](https://github.com/storybookjs/storybook/commits/v6.4.21/addons/actions)

---
updated-dependencies:
- dependency-name: "@storybook/addon-actions"
  dependency-type: direct:development
  update-type: version-update:semver-minor
...

Signed-off-by: dependabot[bot] <support@github.com>