chore(deps): update dependency puma to v8 (#395)

Author: renovate[bot]

contract-tests/Gemfile

@@ -4,7 +4,7 @@ gem 'launchdarkly-server-sdk', path: '..'
 
 gem 'http', '>= 5.1', '< 7.0'
 gem 'json'
-gem "puma", "~> 6.6"
+gem "puma", "~> 8.0"
 gem "rackup", "~> 2.2"
 gem 'sinatra', '>= 4.1'