Build(deps): Bump onebox from 1.9.28.2 to 1.9.28.3 (#9887)

Bumps [onebox](https://github.com/discourse/onebox) from 1.9.28.2 to 1.9.28.3.
- [Release notes](https://github.com/discourse/onebox/releases)
- [Changelog](https://github.com/discourse/onebox/blob/master/CHANGELOG.md)
- [Commits](https://github.com/discourse/onebox/compare/v1.9.28.2...v1.9.28.3)

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

Co-authored-by: dependabot-preview[bot] <27856297+dependabot-preview[bot]@users.noreply.github.com>

Gemfile.lock

@@ -240,7 +240,7 @@ GEM
     omniauth-twitter (1.4.0)
       omniauth-oauth (~> 1.1)
       rack
-    onebox (1.9.28.2)
+    onebox (1.9.28.3)
       addressable (~> 2.7.0)
       htmlentities (~> 4.3)
       multi_json (~> 1.11)