Bump required ruby version to 3.2 or later.

Even though it still actually work with older version of ruby,
it might be better recommending supported Ruby version.

* Ruby 2.7 EOL: 2023-03-31
* Ruby 3.0 EOL: 2024-04-23
* Ruby 3.1 EOL: 2025-03-31

Signed-off-by: Kentaro Hayashi <[email protected]>

Author: kenhys

.github/workflows/test.yml

@@ -26,7 +26,7 @@ jobs:
       fail-fast: false
       matrix:
         os: ['ubuntu-latest', 'macos-latest', 'windows-latest']
-        ruby-version: ['3.4', '3.3', '3.2', '3.1']
+        ruby-version: ['3.4', '3.3', '3.2']
 
     name: Ruby ${{ matrix.ruby-version }} on ${{ matrix.os }}
     steps:

fluentd.gemspec

@@ -20,7 +20,7 @@ Gem::Specification.new do |gem|
   gem.require_paths = ["lib"]
   gem.license = "Apache-2.0"
 
-  gem.required_ruby_version = '>= 2.7'
+  gem.required_ruby_version = '>= 3.2'
 
   gem.add_runtime_dependency("bundler")
   gem.add_runtime_dependency("msgpack", [">= 1.3.1", "< 2.0.0"])