Bump rack from 1.6.4 to 1.6.13

Bumps [rack](https://github.com/rack/rack) from 1.6.4 to 1.6.13.
- [Release notes](https://github.com/rack/rack/releases)
- [Changelog](https://github.com/rack/rack/blob/master/CHANGELOG.md)
- [Commits](rack/rack@1.6.4...1.6.13)

---
updated-dependencies:
- dependency-name: rack
  dependency-type: indirect
...

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

Author: dependabot[bot]

Gemfile.lock

@@ -18,7 +18,7 @@ GEM
     nio4r (2.5.8)
     puma (5.5.2)
       nio4r (~> 2.0)
-    rack (1.6.4)
+    rack (1.6.13)
     rack-protection (1.5.3)
       rack
     rest-client (2.1.0)