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](https://github.com/rack/rack/compare/2.0.7...2.0.8)

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

Gemfile.lock

@@ -158,7 +158,7 @@ GEM
     powerpack (0.1.1)
     public_suffix (3.0.2)
     puma (3.12.2)
-    rack (2.0.7)
+    rack (2.0.8)
     rack-canonical-host (0.2.3)
       addressable (> 0, < 3)
       rack (>= 1.0.0, < 3)