Bump rack from 2.2.6.2 to 2.2.6.4 (#2753)

Bumps [rack](https://github.com/rack/rack) from 2.2.6.2 to 2.2.6.4.
- [Release notes](https://github.com/rack/rack/releases)
- [Changelog](https://github.com/rack/rack/blob/main/CHANGELOG.md)
- [Commits](https://github.com/rack/rack/compare/v2.2.6.2...v2.2.6.4)

---
updated-dependencies:
- dependency-name: rack
  dependency-type: direct:production
  update-type: version-update:semver-patch
...

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

Gemfile.lock

@@ -131,7 +131,7 @@ GEM
       mojo_magick (~> 0.6.5)
       rqrcode_core (~> 0.1)
     racc (1.6.1)
-    rack (2.2.6.2)
+    rack (2.2.6.4)
     rack-protection (3.0.5)
       rack
     rack-test (2.0.2)