Bump @storybook/addon-essentials from 8.6.15 to 8.6.18

Bumps [@storybook/addon-essentials](https://github.com/storybookjs/storybook/tree/HEAD/code/addons/essentials) from 8.6.15 to 8.6.18.
- [Release notes](https://github.com/storybookjs/storybook/releases)
- [Changelog](https://github.com/storybookjs/storybook/blob/v8.6.18/CHANGELOG.md)
- [Commits](https://github.com/storybookjs/storybook/commits/v8.6.18/code/addons/essentials)

---
updated-dependencies:
- dependency-name: "@storybook/addon-essentials"
  dependency-version: 8.6.18
  dependency-type: direct:development
  update-type: version-update:semver-patch
...

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Author: dependabot[bot]