[rubygems/rubygems] Close then unlink tempfiles on Windows

In ruby/ruby test actions, number of "leaked tempfile" messages
are shown on Windows.

As Windows disallows removing open files, `Tempfile#unlink` fails
silently before `#close`.
Close then unlink by `#close!` instead.

https://github.com/rubygems/rubygems/commit/fe0b88ac30

test/rubygems/helper.rb

@@ -153,15 +153,13 @@ class Gem::TestCase < Test::Unit::TestCase
 
         return captured_stdout.read, captured_stderr.read
       ensure
-        captured_stdout.unlink
-        captured_stderr.unlink
         $stdout.reopen orig_stdout
         $stderr.reopen orig_stderr
 
         orig_stdout.close
         orig_stderr.close
-        captured_stdout.close
-        captured_stderr.close
+        captured_stdout.close!
+        captured_stderr.close!
       end
     end
   end