chore: Bump rack from 3.1.5 to 3.1.7 (#860)

Bumps [rack](https://github.com/rack/rack) from 3.1.5 to 3.1.7.
- [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/v3.1.5...v3.1.7)

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

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

Gemfile.lock

@@ -220,7 +220,7 @@ GEM
       stringio
     public_suffix (5.0.5)
     racc (1.8.1)
-    rack (3.1.5)
+    rack (3.1.7)
     rack-session (2.0.0)
       rack (>= 3.0.0)
     rack-test (2.1.0)
@@ -334,7 +334,7 @@ DEPENDENCIES
   mini_racer (~> 0.13.0)
   minima!
   nokogiri (>= 1.10.4)
-  rack (~> 3.1.5)
+  rack (~> 3.1.7)
   railties (>= 5.2.2.1)
   rouge
   rubocop