Reapply "Remove needless task"

This reverts commit d62681e.

Author: sue445

Rakefile

@@ -9,13 +9,6 @@ end
 
 Dir["#{__dir__}/_tasks/*.rake"].each { |f| load f }
 
-desc "Release package"
-task :release do
-  Dir.chdir(File.join(__dir__, "_gem")) do
-    sh "rake release"
-  end
-end
-
 desc "Generate changelog entry"
 task :changelog, [:before, :after] do |_, params|
   args = []