Drop ruby 2.5

Author: nobu

.github/workflows/test.yml

@@ -6,7 +6,7 @@ jobs:
   ruby-versions:
     uses: ruby/actions/.github/workflows/ruby_versions.yml@master
     with:
-      min_version: 2.5
+      min_version: 2.6
   test:
     needs: ruby-versions
     name: build (${{ matrix.ruby }} / ${{ matrix.os }})
@@ -16,7 +16,6 @@ jobs:
         ruby: ${{ fromJson(needs.ruby-versions.outputs.versions) }}
         os: [ ubuntu-latest, macos-latest, windows-latest ]
         exclude:
-          - { os: macos-latest, ruby: 2.5 }
           - { os: windows-latest, ruby: head }
           - { os: macos-latest, ruby: jruby }
           - { os: windows-latest, ruby: jruby }

cgi.gemspec

@@ -17,7 +17,7 @@ Gem::Specification.new do |spec|
   spec.description   = %q{Support for the Common Gateway Interface protocol.}
   spec.homepage      = "https://github.com/ruby/cgi"
   spec.licenses      = ["Ruby", "BSD-2-Clause"]
-  spec.required_ruby_version = ">= 2.5.0"
+  spec.required_ruby_version = ">= 2.6.0"
 
   spec.metadata["homepage_uri"] = spec.homepage
   spec.metadata["source_code_uri"] = spec.homepage