Bump rack from 1.5.2 to 1.6.13 in /api/ruby/delivering-deployments

Bumps [rack](https://github.com/rack/rack) from 1.5.2 to 1.6.13.
- [Release notes](https://github.com/rack/rack/releases)
- [Changelog](https://github.com/rack/rack/blob/main/CHANGELOG.md)
- [Commits](rack/rack@1.5.2...1.6.13)

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

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

Author: dependabot[bot]

api/ruby/delivering-deployments/Gemfile.lock

@@ -1,5 +1,5 @@
 GEM
-  remote: http://rubygems.org/
+  remote: https://rubygems.org/
   specs:
     addressable (2.3.6)
     faraday (0.9.0)
@@ -8,7 +8,7 @@ GEM
     multipart-post (2.0.0)
     octokit (3.0.0)
       sawyer (~> 0.5.3)
-    rack (1.5.2)
+    rack (1.6.13)
     rack-protection (1.5.2)
       rack
     sawyer (0.5.4)