Bump rack from 3.1.7 to 3.1.12

Bumps [rack](https://github.com/rack/rack) from 3.1.7 to 3.1.12.
- [Release notes](https://github.com/rack/rack/releases)
- [Changelog](https://github.com/rack/rack/blob/main/CHANGELOG.md)
- [Commits](rack/rack@v3.1.7...v3.1.12)

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

Signed-off-by: dependabot[bot] <[email protected]>

Author: dependabot[bot]

Gemfile.lock

@@ -30,7 +30,7 @@ GEM
     link_header (0.0.8)
     matrix (0.4.2)
     multi_json (1.15.0)
-    rack (3.1.7)
+    rack (3.1.12)
     rake (13.2.1)
     rdf (3.3.2)
       bcp47_spec (~> 0.2)