Bump puma from 5.3.2 to 5.6.4

Bumps [puma](https://github.com/puma/puma) from 5.3.2 to 5.6.4.
- [Release notes](https://github.com/puma/puma/releases)
- [Changelog](https://github.com/puma/puma/blob/master/History.md)
- [Commits](puma/puma@v5.3.2...v5.6.4)

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

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

Gemfile

@@ -11,7 +11,7 @@ gem 'rails', '~> 6.1.3', '>= 6.1.3.2'
 # Use sqlite3 as the database for Active Record
 gem 'sqlite3', '~> 1.4'
 # Use Puma as the app server
-gem 'puma', '~> 5.0'
+gem 'puma', '~> 5.6'
 # Use SCSS for stylesheets
 gem 'sass-rails', '>= 6'
 # Transpile app-like JavaScript. Read more: https://github.com/rails/webpacker

Gemfile.lock

@@ -99,14 +99,14 @@ GEM
     mini_mime (1.0.3)
     minitest (5.14.4)
     msgpack (1.4.2)
-    nio4r (2.5.7)
+    nio4r (2.5.8)
     nokogiri (1.11.7-x86_64-darwin)
       racc (~> 1.4)
     nokogiri (1.11.7-x86_64-linux)
       racc (~> 1.4)
     pg (1.2.3)
     public_suffix (4.0.6)
-    puma (5.3.2)
+    puma (5.6.4)
       nio4r (~> 2.0)
     racc (1.5.2)
     rack (2.2.3)
@@ -210,7 +210,7 @@ DEPENDENCIES
   jbuilder (~> 2.7)
   listen (~> 3.3)
   pg (~> 1.2)
-  puma (~> 5.0)
+  puma (~> 5.6)
   rack-mini-profiler (~> 2.0)
   rails (~> 6.1.3, >= 6.1.3.2)
   sass-rails (>= 6)