Bump view_component from 3.14.0 to 3.15.0 in /demo

Bumps [view_component](https://github.com/viewcomponent/view_component) from 3.14.0 to 3.15.0.
- [Release notes](https://github.com/viewcomponent/view_component/releases)
- [Changelog](https://github.com/ViewComponent/view_component/blob/main/docs/CHANGELOG.md)
- [Commits](ViewComponent/view_component@v3.14.0...v3.15.0)

---
updated-dependencies:
- dependency-name: view_component
  dependency-type: direct:production
  update-type: version-update:semver-minor
...

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

demo/Gemfile.lock

@@ -332,7 +332,7 @@ GEM
       railties (>= 6.0.0)
     tzinfo (2.0.6)
       concurrent-ruby (~> 1.0)
-    view_component (3.14.0)
+    view_component (3.15.0)
       activesupport (>= 5.2.0, < 8.0)
       concurrent-ruby (~> 1.0)
       method_source (~> 1.0)