Upgrade Puma to 6 for compatibility

Gemfile

@@ -3,7 +3,7 @@ source "https://rubygems.org"
 gem "rails", "~> 7.1.2"
 gem "sprockets-rails"
 gem "mysql2", "~> 0.5"
-gem "puma", "~> 5.0"
+gem "puma", "~> 6.0"
 gem "sassc-rails"
 # Windows does not include zoneinfo files, so bundle the tzinfo-data gem
 gem "tzinfo-data", platforms: %i[ mingw mswin x64_mingw jruby ]

Gemfile.lock

@@ -150,7 +150,7 @@ GEM
     psych (5.1.2)
       stringio
     public_suffix (5.0.4)
-    puma (5.6.7)
+    puma (6.4.1)
       nio4r (~> 2.0)
     racc (1.7.3)
     rack (3.0.8)
@@ -257,7 +257,7 @@ DEPENDENCIES
   devise
   importmap-rails
   mysql2 (~> 0.5)
-  puma (~> 5.0)
+  puma (~> 6.0)
   rails (~> 7.1.2)
   sassc-rails
   selenium-webdriver