Bump up required ruby version to 3.1

.github/workflows/reviewdog.yml

@@ -17,7 +17,7 @@ jobs:
       uses: ruby/setup-ruby@v1
       with:
         bundler-cache: true
-        ruby-version: '3.0'
+        ruby-version: '3.1'
 
     - name: rubocop
       uses: reviewdog/action-rubocop@v2

.github/workflows/ruby_test.yml

@@ -11,13 +11,13 @@ jobs:
     runs-on: ubuntu-latest
     strategy:
       matrix:
-        ruby-version: ['2.7', '3.0', '3.1']
+        ruby-version: ["3.1", "3.2", "3.3"]
     steps:
-    - uses: actions/checkout@v3
-    - name: Set up Ruby
-      uses: ruby/setup-ruby@v1
-      with:
-        ruby-version: ${{ matrix.ruby-version }}
-        bundler-cache: true # runs 'bundle install' and caches installed gems automatically
-    - name: Run tests
-      run: bundle exec rake test
+      - uses: actions/checkout@v3
+      - name: Set up Ruby
+        uses: ruby/setup-ruby@v1
+        with:
+          ruby-version: ${{ matrix.ruby-version }}
+          bundler-cache: true # runs 'bundle install' and caches installed gems automatically
+      - name: Run tests
+        run: bundle exec rake test

.rubocop.yml

@@ -3,7 +3,7 @@ require:
   - rubocop-performance
 
 AllCops:
-  TargetRubyVersion: 2.7
+  TargetRubyVersion: 3.1
   DisplayCopNames: true
   Exclude:
     - bin/**/*

mato.gemspec

@@ -25,7 +25,7 @@ Gem::Specification.new do |spec|
   spec.executables   = spec.files.grep(%r{^exe/}) { |f| File.basename(f) }
   spec.require_paths = ["lib"]
 
-  spec.required_ruby_version = ">= 2.7"
+  spec.required_ruby_version = "~> 3.1"
 
   spec.add_runtime_dependency "commonmarker", "~> 1.0"
   spec.add_runtime_dependency "markly", "~> 0.9"