Bump rack from 2.2.6.2 to 2.2.6.4 in /app/ruby/app-issue-creator

Bumps [rack](https://github.com/rack/rack) from 2.2.6.2 to 2.2.6.4.
- [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...v2.2.6.4)

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

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

Author: dependabot[bot]

app/ruby/app-issue-creator/Gemfile.lock

@@ -44,7 +44,7 @@ GEM
     octokit (4.7.0)
       sawyer (~> 0.8.0, >= 0.5.3)
     public_suffix (5.0.1)
-    rack (2.2.6.2)
+    rack (2.2.6.4)
     rack-protection (2.2.3)
       rack
     ruby2_keywords (0.0.5)