Bump puma from 5.6.2 to 5.6.4

Bumps [puma](https://github.com/puma/puma) from 5.6.2 to 5.6.4.
- [Release notes](https://github.com/puma/puma/releases)
- [Changelog](https://github.com/puma/puma/blob/master/History.md)
- [Commits](https://github.com/puma/puma/compare/v5.6.2...v5.6.4)

---
updated-dependencies:
- dependency-name: puma
  dependency-type: direct:production
...

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

Gemfile.lock

@@ -707,7 +707,7 @@ GEM
       eventmachine_httpserver
       http_parser.rb (~> 0.6.0)
       multi_json
-    puma (5.6.2)
+    puma (5.6.4)
       nio4r (~> 2.0)
     puma-plugin-statsd (2.1.0)
       puma (>= 5.0, < 6)