build(deps): 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

@@ -265,7 +265,7 @@ GEM
     public_suffix (4.0.1)
     puma (4.3.1)
       nio4r (~> 2.0)
-    rack (2.0.7)
+    rack (2.0.8)
     rack-contrib (2.1.0)
       rack (~> 2.0)
     rack-mini-profiler (1.1.4)