Drop Ruby 3.0 support

.rubocop.yml

@@ -6,7 +6,7 @@ require:
 
 AllCops:
     EnabledByDefault: true
-    TargetRubyVersion: 3.0
+    TargetRubyVersion: 3.1
 
 Bundler/GemComment:
   Enabled: false
@@ -91,6 +91,9 @@ Style/GlobalVars:
     - 'ext/ilios/extconf.rb'
     - 'test/helper.rb'
 
+Style/HashSyntax:
+  EnforcedShorthandSyntax: either
+
 Style/IpAddresses:
   Enabled: false
 

Gemfile

@@ -10,8 +10,8 @@ gem 'rake', '~> 13.0'
 gem 'rake-compiler', '~> 1.2'
 gem 'rbs', '~> 3.4'
 gem 'rubocop', '~> 1.57'
-gem 'rubocop-minitest', '~> 0.33.0'
+gem 'rubocop-minitest', '~> 0.33'
 gem 'rubocop-performance', '~> 1.19'
 gem 'rubocop-rake', '~> 0.6'
 
-gem 'rubocop-on-rbs', '~> 0.2' if Gem::Version.new(RUBY_VERSION) >= Gem::Version.new('3.1')
+gem 'rubocop-on-rbs', '~> 0.2'

ilios.gemspec

@@ -12,7 +12,7 @@ Gem::Specification.new do |spec|
   spec.description = 'Cassandra driver written by C language'
   spec.homepage = 'https://github.com/Watson1978/ilios'
   spec.license = 'MIT'
-  spec.required_ruby_version = '>= 3.0.0'
+  spec.required_ruby_version = '>= 3.1.0'
 
   spec.requirements << 'cmake'