Bump @storybook/server from 6.3.3 to 6.3.4

Bumps [@storybook/server](https://github.com/storybookjs/storybook/tree/HEAD/app/server) from 6.3.3 to 6.3.4.
- [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/v6.3.4/app/server)

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

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

package.json

@@ -11,7 +11,7 @@
   "devDependencies": {
     "@storybook/addon-controls": "^6.3.3",
     "@storybook/addon-docs": "^6.3.4",
-    "@storybook/server": "^6.3.3",
+    "@storybook/server": "^6.3.4",
     "jasmine-core": "~2.4.1",
     "karma": "~6.3.4",
     "karma-chrome-launcher": "~3.1.0",