Bump rack from 2.2.3 to 2.2.6.4 in /cookbooks/datadog (#141)

Bumps [rack](https://github.com/rack/rack) from 2.2.3 to 2.2.6.4.
- [Release notes](https://github.com/rack/rack/releases)
- [Changelog](https://github.com/rack/rack/blob/main/CHANGELOG.md)
- [Commits](rack/rack@2.2.3...v2.2.6.4)

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

Signed-off-by: dependabot[bot] <[email protected]>
Co-authored-by: dependabot[bot] <49699333+dependabot[bot]@users.noreply.github.com>

cookbooks/datadog/Gemfile.lock

@@ -224,7 +224,7 @@ GEM
     proxifier (1.0.3)
     public_suffix (4.0.6)
     racc (1.6.0)
-    rack (2.2.3)
+    rack (2.2.6.4)
     rainbow (3.0.0)
     rake (13.0.1)
     rbnacl (4.0.2)