Bump @storybook/addon-a11y from 7.6.4 to 7.6.9 in /extensions/ql-vscode

Bumps [@storybook/addon-a11y](https://github.com/storybookjs/storybook/tree/HEAD/code/addons/a11y) from 7.6.4 to 7.6.9.
- [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/v7.6.9/code/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>

Author: dependabot[bot]

extensions/ql-vscode/package-lock.json

@@ -1971,7 +1971,7 @@
     "@faker-js/faker": "^8.0.2",
     "@github/markdownlint-github": "^0.6.0",
     "@octokit/plugin-throttling": "^8.0.0",
-    "@storybook/addon-a11y": "^7.4.6",
+    "@storybook/addon-a11y": "^7.6.9",
     "@storybook/addon-actions": "^7.1.0",
     "@storybook/addon-essentials": "^7.1.0",
     "@storybook/addon-interactions": "^7.1.0",