Bump rack from 3.1.16 to 3.1.18 in the bundler group across 1 directory (#1155)

Bumps the bundler group with 1 update in the / directory: [rack](https://github.com/rack/rack).


Updates `rack` from 3.1.16 to 3.1.18
- [Release notes](https://github.com/rack/rack/releases)
- [Changelog](https://github.com/rack/rack/blob/main/CHANGELOG.md)
- [Commits](rack/rack@v3.1.16...v3.1.18)

---
updated-dependencies:
- dependency-name: rack
  dependency-version: 3.1.18
  dependency-type: indirect
  dependency-group: bundler
...

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

Author: dependabot[bot]

Gemfile.lock

@@ -147,7 +147,7 @@ GEM
       forwardable-extended (~> 2.6)
     public_suffix (6.0.1)
     racc (1.8.1)
-    rack (3.1.16)
+    rack (3.1.18)
     rake (13.3.0)
     rb-fsevent (0.11.2)
     rb-inotify (0.11.1)