(#22878) Scope call to CloseHandle

Previously, the win32-process gem used to extend Windows::Handle from the
windows-pr gem, so that the Process.CloseHandle method was available.
However, newer versions of the win32-process gem that are based on ffi, do
not extend Windows::Handle, so the Process.CloseHandle method is not defined.

This commit modifies puppet to call a version of CloseHandle which we
control, and therefore is guaranteed to exist.
Merge branch 'ticket/stable/22878-close-handle' into stable

* ticket/stable/22878-close-handle:
  (#22878) Scope call to CloseHandle
(maint) Remove stale files from ext/rack

The ext/rack directory had an outdated README file and an ancient manifest.pp
file, and the useful files (config.ru and the example vhost) were buried in a
subdirectory.

This commit removes the old files, moves the good files up a level, and adds a
comment to the vhost pointing to the maintained passenger documentation.
(maint) Update debian packaging to reference new rack support location

As updated in commit 4c9b63f, the sample files for rack passenger deployment
have been moved up a directory. The puppetmaster-passenger package for debian
uses those files, so this commit updates the debian/rules file with their new
location. It also updates the README_DEVELOPER.md, which references the same
files.