Bump rack from 2.2.6.3 to 2.2.6.4
Bumps [rack](https://github.com/rack/rack) from 2.2.6.3 to 2.2.6.4.
- [Release notes](https://github.com/rack/rack/releases)
- [Changelog](https://github.com/rack/rack/blob/main/CHANGELOG.md)
- [Commits](https://github.com/rack/rack/compare/v2.2.6.3...v2.2.6.4)
---
updated-dependencies:
- dependency-name: rack
dependency-type: indirect
...
Signed-off-by: dependabot[bot] <support@github.com>