Add CSV gem to gemspec for Ruby 3.4

[zavan]

warning: /Users/zavan/.asdf/installs/ruby/3.3.3/lib/ruby/3.3.0/csv.rb was loaded from the standard library, but will no longer be part of the default gems since Ruby 3.4.0. Add csv to your Gemfile or gemspec. Also contact author of spree_i18n-5.3.0 to add csv into its gemspec.