feat(dev): prepare for 3.4.0

- include 3.4.0-preview2 in GitHub workflow
- add gem 'csv' to dependency list → it is no longer part of the default
  gems / stdlib

.github/workflows/main.yml

@@ -18,6 +18,7 @@ jobs:
           - '3.1'
           - '3.2'
           - '3.3'
+          - '3.4.0-preview2'
 
     steps:
     - uses: actions/checkout@v4

Gemfile.lock

@@ -2,11 +2,13 @@ PATH
   remote: .
   specs:
     human_languages (0.8.0)
+      csv (~> 3.0)
 
 GEM
   remote: https://rubygems.org/
   specs:
     ast (2.4.2)
+    csv (3.3.0)
     json (2.8.2)
     language_server-protocol (3.17.0.3)
     minitest (5.25.1)
@@ -50,4 +52,4 @@ DEPENDENCIES
   rubocop-rake (~> 0.6.0)
 
 BUNDLED WITH
-   2.3.7
+   2.5.6

human_languages.gemspec

@@ -33,8 +33,7 @@ Gem::Specification.new do |spec|
   spec.executables = spec.files.grep(%r{\Aexe/}) { |f| File.basename(f) }
   spec.require_paths = ['lib']
 
-  # Uncomment to register a new dependency of your gem
-  # spec.add_dependency "example-gem", "~> 1.0"
+  spec.add_dependency('csv', '~> 3.0') if Gem::Version.new(RUBY_VERSION) >= Gem::Version.new('3.3')
 
   # For more information and examples about making a new gem, check out our
   # guide at: https://bundler.io/guides/creating_gem.html