Bump rack from 2.0.7 to 2.0.8

Bumps [rack](https://github.com/rack/rack) from 2.0.7 to 2.0.8.
- [Release notes](https://github.com/rack/rack/releases)
- [Changelog](https://github.com/rack/rack/blob/master/CHANGELOG.md)
- [Commits](rack/rack@2.0.7...2.0.8)

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

Author: dependabot[bot]

Gemfile.lock

@@ -111,7 +111,7 @@ GEM
       binding_of_caller (>= 0.7)
       pry (>= 0.9.11)
     puma (3.11.0)
-    rack (2.0.7)
+    rack (2.0.8)
     rack-attack (5.0.1)
       rack
     rack-cors (1.0.5)