Bump rack from 2.2.6.2 to 2.2.6.3

Bumps [rack](https://github.com/rack/rack) from 2.2.6.2 to 2.2.6.3.
- [Release notes](https://github.com/rack/rack/releases)
- [Changelog](https://github.com/rack/rack/blob/main/CHANGELOG.md)
- [Commits](rack/rack@v2.2.6.2...v2.2.6.3)

---
updated-dependencies:
- dependency-name: rack
  dependency-type: indirect
...

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

Author: dependabot[bot]

Gemfile.lock

@@ -91,7 +91,7 @@ GEM
       nokogiri (~> 1.8, >= 1.8.4)
     public_suffix (4.0.6)
     racc (1.6.1)
-    rack (2.2.6.2)
+    rack (2.2.6.3)
     rake (13.0.6)
     rdf (3.2.5)
       link_header (~> 0.0, >= 0.0.8)