Update gemspec files

[simon-isler]

irb(main):017* Dir.chdir(File.expand_path(__dir__)) do
irb(main):018*     `git ls-files -z`.split("\x0").reject { |f| f.match(%r{^(test|spec|features|docs)/}) || f.end_with?(".gem") }
irb(main):019> end - Dir["{app,config,lib}/**/*", "CHANGELOG.md", "README.md"]
=> 
[".github/CODEOWNERS",
 ".gitignore",
 ".ruby-version",
 ".semaphore/main-deploy.yml",
 ".semaphore/semaphore.yml",
 "Appraisals",
 "Gemfile",
 "Rakefile",
 "app/assets/images/moirai/.keep",
 "app/controllers/concerns/.keep",
 "app/models/concerns/.keep",
 "bin/check",
 "bin/console",
 "bin/fastcheck",
 "bin/rails",
 "bin/setup",
 "moirai.gemspec"]