chore(deps-dev): bump storybook from 7.5.3 to 7.6.21 in /packages/ui

Bumps [storybook](https://github.com/storybookjs/storybook/tree/HEAD/code/core) from 7.5.3 to 7.6.21.
- [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/v7.6.21/code/core)

---
updated-dependencies:
- dependency-name: storybook
  dependency-version: 7.6.21
  dependency-type: direct:development
...

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

packages/ui/package.json

@@ -74,7 +74,7 @@
     "postcss": "^8.4.31",
     "postcss-loader": "^7.3.3",
     "postcss-nesting": "^12.0.1",
-    "storybook": "^7.5.3",
+    "storybook": "^7.6.21",
     "string-width": "4.2.0",
     "strip-ansi": "^6",
     "style-loader": "3.3.1"