Bump puma from 3.12.0 to 4.3.1

Bumps [puma](https://github.com/puma/puma) from 3.12.0 to 4.3.1.
- [Release notes](https://github.com/puma/puma/releases)
- [Changelog](https://github.com/puma/puma/blob/master/History.md)
- [Commits](puma/puma@v3.12.0...v4.3.1)

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

Author: dependabot[bot]

Gemfile.lock

@@ -132,7 +132,8 @@ GEM
       cliver (~> 0.3.1)
       websocket-driver (>= 0.2.0)
     public_suffix (3.0.3)
-    puma (3.12.0)
+    puma (4.3.1)
+      nio4r (~> 2.0)
     rack (2.0.7)
     rack-proxy (0.6.5)
       rack