Bump @storybook/addon-a11y from 6.5.14 to 6.5.15

Bumps [@storybook/addon-a11y](https://github.com/storybookjs/storybook/tree/HEAD/addons/a11y) from 6.5.14 to 6.5.15.
- [Release notes](https://github.com/storybookjs/storybook/releases)
- [Changelog](https://github.com/storybookjs/storybook/blob/v6.5.15/CHANGELOG.md)
- [Commits](https://github.com/storybookjs/storybook/commits/v6.5.15/addons/a11y)

---
updated-dependencies:
- dependency-name: "@storybook/addon-a11y"
  dependency-type: direct:development
  update-type: version-update:semver-patch
...

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

src/Umbraco.Web.UI.Client/package.json

@@ -74,7 +74,7 @@
 		"@mdx-js/react": "^2.2.1",
 		"@open-wc/testing": "^3.1.7",
 		"@playwright/test": "^1.29.0",
-		"@storybook/addon-a11y": "^6.5.14",
+		"@storybook/addon-a11y": "^6.5.15",
 		"@storybook/addon-actions": "^6.5.14",
 		"@storybook/addon-essentials": "^6.5.14",
 		"@storybook/addon-links": "^6.5.14",