Update required Ruby version to 3.1.0

Author: hahwul

.github/workflows/ci.yml

@@ -15,7 +15,7 @@ jobs:
     runs-on: ubuntu-latest
     strategy:
       matrix:
-        ruby-version: ['2.7', '3.0', '3.1', '3.2', '3.3']
+        ruby-version: ['3.1', '3.2', '3.3']
 
     steps:
     - uses: actions/checkout@v4

caido.gemspec

@@ -11,7 +11,7 @@ Gem::Specification.new do |spec|
   spec.summary = 'Ruby implementation of Caido'
   spec.description = 'Tuby implementation of Caido'
   spec.homepage = 'https://github.com/caineers/caido-ruby'
-  spec.required_ruby_version = '>= 2.7.0'
+  spec.required_ruby_version = '>= 3.1.0'
 
   spec.metadata['homepage_uri'] = spec.homepage
   spec.metadata['source_code_uri'] = 'https://github.com/caineers/caido-ruby'