Bump rack from 2.2.6.3 to 2.2.6.4

Bumps [rack](https://github.com/rack/rack) from 2.2.6.3 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@v2.2.6.3...v2.2.6.4)

---
updated-dependencies:
- dependency-name: rack
  dependency-type: direct:production
...

Signed-off-by: dependabot[bot] <[email protected]>

Author: dependabot[bot]

Gemfile.lock

@@ -85,7 +85,7 @@ GEM
     parallel (1.22.1)
     parslet (2.0.0)
     public_suffix (5.0.1)
-    rack (2.2.6.3)
+    rack (2.2.6.4)
     rb-fsevent (0.11.2)
     rb-inotify (0.10.1)
       ffi (~> 1.0)