[ruby/net-http] Exclude git related files

https://github.com/ruby/net-http/commit/2767df580d

lib/net/http/net-http.gemspec

@@ -30,7 +30,7 @@ Gem::Specification.new do |spec|
   # Specify which files should be added to the gem when it is released.
   # The `git ls-files -z` loads the files in the RubyGem that have been added into git.
   spec.files         = Dir.chdir(File.expand_path('..', __FILE__)) do
-    `git ls-files -z 2>/dev/null`.split("\x0").reject { |f| f.match(%r{^(test|spec|features)/}) }
+    `git ls-files -z 2>/dev/null`.split("\x0").reject { |f| f.match(%r{\A(?:(?:test|spec|features)/|\.git)}) }
   end
   spec.bindir        = "exe"
   spec.require_paths = ["lib"]