Bump rack from 2.0.5 to 2.0.8

Bumps [rack](https://github.com/rack/rack) from 2.0.5 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/2.0.5...2.0.8)

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

Gemfile.lock

@@ -77,7 +77,7 @@ GEM
       mini_portile2 (~> 2.3.0)
     pg (1.1.3)
     puma (3.12.0)
-    rack (2.0.5)
+    rack (2.0.8)
     rack-cors (1.0.2)
     rack-test (1.1.0)
       rack (>= 1.0, < 3)