CI: Support Ruby 3.5

[Watson1978]

Ractor#take was replaced at Ruby 3.5.
https://bugs.ruby-lang.org/issues/21262

This patch will fix following error with Ruby 3.5 dev:

Failures:

  1) Zstd::StreamingCompress Ractor should be supported
     Failure/Error: expect(Zstd.decompress(r.take)).to eq('abcdef')
     
     NoMethodError:
       undefined method 'take' for an instance of Ractor
     # ./spec/zstd-ruby-streaming-compress_spec.rb:118:in 'block (3 levels) in <top (required)>'

  2) Zstd::StreamingDecompress Ractor should be supported
     Failure/Error: expect(r.take).to eq('foo bar buzz')
     
     NoMethodError:
       undefined method 'take' for an instance of Ractor
     # ./spec/zstd-ruby-streaming-decompress_spec.rb:172:in 'block (3 levels) in <top (required)>'

  3) Zstd Ractor should be supported
     Failure/Error: expect(Zstd.decompress(r.take)).to eq('abc')
     
     NoMethodError:
       undefined method 'take' for an instance of Ractor
     # ./spec/zstd-ruby_spec.rb:121:in 'block (3 levels) in <top (required)>'