chore(deps-dev): bump storybook from 8.1.11 to 8.6.15

Bumps [storybook](https://github.com/storybookjs/storybook/tree/HEAD/code/core) from 8.1.11 to 8.6.15.
- [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/v8.6.15/code/core)

---
updated-dependencies:
- dependency-name: storybook
  dependency-version: 8.6.15
  dependency-type: direct:development
...

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

Author: dependabot[bot]

package.json

@@ -266,7 +266,7 @@
     "slate-history": "0.109.0",
     "slate-react": "0.110.1",
     "source-map-loader": "3.0.0",
-    "storybook": "^8.1.11",
+    "storybook": "^8.6.15",
     "stream-browserify": "3.0.0",
     "style-loader": "3.3.1",
     "styled-components": "5.3.5",