Ruby warning: "assigned but unused variable - derived_key"

[jessevdp]

Hey!

It seems there's a (small) "problem" in this Gems code that's causing a Ruby warning.
(I'm seeing the warning in the output of my test suite, which uses the JOSE Gem 😄)

Would you be open to a "fix"?

Details

# reproduction_case.rb
require 'bundler/inline'

gemfile do
  source 'https://rubygems.org'
  gem 'jose'
end

require 'jose'

$ ruby -w reproduction_case.rb
/Users/<me>/.rbenv/versions/3.2.2/lib/ruby/gems/3.2.0/gems/jose-1.2.0/lib/jose/jwe/alg_xc20p_kw.rb:64: warning: assigned but unused variable - derived_key

The seemingly unused variable:

ruby-jose/lib/jose/jwe/alg_xc20p_kw.rb

Line 64 in c3943f4

derived_key = key