Bump puma from 6.3.1 to 6.4.2

Bumps [puma](https://github.com/puma/puma) from 6.3.1 to 6.4.2.
- [Release notes](https://github.com/puma/puma/releases)
- [Changelog](https://github.com/puma/puma/blob/master/History.md)
- [Commits](puma/puma@v6.3.1...v6.4.2)

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

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

Gemfile.lock

@@ -9,8 +9,8 @@ GEM
   remote: https://rubygems.org/
   specs:
     minitest (5.15.0)
-    nio4r (2.5.9)
-    puma (6.3.1)
+    nio4r (2.7.0)
+    puma (6.4.2)
       nio4r (~> 2.0)
     rack (3.0.8)
     raindrops (0.20.1)