Revert adding ruby tarball to gem package

Author: kateinoigakukun

ruby_wasm.gemspec

@@ -23,7 +23,7 @@ Gem::Specification.new do |spec|
     `git ls-files -z`.split("\x0").reject do |f|
       (f == __FILE__) || f.match(%r{\A(?:(?:bin|test|spec|features)/|\.(?:git|travis|circleci)|appveyor)})
     end
-  end + ["rubies/ruby-head-wasm32-unknown-wasi-full.tar.gz"]
+  end
   spec.bindir = "exe"
   spec.executables = spec.files.grep(%r{\Aexe/}) { |f| File.basename(f) }
   spec.require_paths = ["lib"]