Bump rack from 3.1.15 to 3.1.16 in the bundler group

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


Updates `rack` from 3.1.15 to 3.1.16
- [Release notes](https://github.com/rack/rack/releases)
- [Changelog](https://github.com/rack/rack/blob/main/CHANGELOG.md)
- [Commits](rack/rack@v3.1.15...v3.1.16)

---
updated-dependencies:
- dependency-name: rack
  dependency-version: 3.1.16
  dependency-type: indirect
  dependency-group: bundler
...

Signed-off-by: dependabot[bot] <support@github.com>

Author: dependabot[bot]

Gemfile.lock

@@ -442,7 +442,7 @@ GEM
       activesupport (>= 3.0.0)
     raabro (1.4.0)
     racc (1.8.1)
-    rack (3.1.15)
+    rack (3.1.16)
     rack-oauth2 (2.2.1)
       activesupport
       attr_required