[Security] Bump rack from 2.0.7 to 2.2.3

Bumps [rack](https://github.com/rack/rack) from 2.0.7 to 2.2.3. **This update includes security fixes.**
- [Release notes](https://github.com/rack/rack/releases)
- [Changelog](https://github.com/rack/rack/blob/master/CHANGELOG.md)
- [Commits](https://github.com/rack/rack/compare/2.0.7...2.2.3)

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

Gemfile.lock

@@ -208,7 +208,7 @@ GEM
     popper_js (1.14.5)
     public_suffix (4.0.1)
     puma (3.12.1)
-    rack (2.0.7)
+    rack (2.2.3)
     rack-cors (1.0.3)
     rack-proxy (0.6.4)
       rack