Refs #38856 - bump ruby requirement to 3.0 to match Dynflow

Author: ianballou

.rubocop.yml

@@ -27,7 +27,7 @@ AllCops:
     - '**/*.rb'
     - app/views/**/*.rabl
     - '**/*.rake'
-  TargetRubyVersion: 2.7
+  TargetRubyVersion: 3.0
 
 Metrics/MethodLength:
   Description: 'Avoid methods longer than 30 lines of code.'

katello.gemspec

@@ -13,7 +13,7 @@ Gem::Specification.new do |gem|
   gem.homepage    = "http://www.katello.org"
   gem.summary     = "Content and Subscription Management plugin for Foreman"
   gem.description = "Katello adds Content and Subscription Management to Foreman. For this it relies on Candlepin and Pulp."
-  gem.required_ruby_version = '>= 2.7', '< 4'
+  gem.required_ruby_version = '>= 3.0', '< 4'
 
   gem.files = Dir["{app,webpack,vendor,lib,db,ca,config,locale}/**/*"] +
     Dir['LICENSE.txt', 'README.md', 'package.json']