Bump rack from 3.1.7 to 3.1.8

Bumps [rack](https://github.com/rack/rack) from 3.1.7 to 3.1.8.
- [Release notes](https://github.com/rack/rack/releases)
- [Changelog](https://github.com/rack/rack/blob/main/CHANGELOG.md)
- [Commits](rack/rack@v3.1.7...v3.1.8)

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

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

Gemfile.lock

@@ -64,7 +64,7 @@ GEM
       method_source (~> 1.0)
     public_suffix (5.0.5)
     racc (1.7.3)
-    rack (3.1.7)
+    rack (3.1.8)
     rack-test (2.1.0)
       rack (>= 1.3)
     rainbow (3.1.1)