(PUP-11095) Align user password management method on all macOS versions

Before this commit, user password management was being special cased on
`macOS 10.14`. The plist of the managed user was being saved directly to
target on disk rather than being written in a temporary file which was
later being imported using `dsimport`.

This commit aligns the behaviour on all macOS versions by choosing the
later variant  due to some transient errors seen in CI where writing to
said plist resulted in a `Operation not permitted @ rb_sysopen` error.

Author: luchihoratiu

lib/puppet/provider/user/directoryservice.rb

@@ -591,11 +591,7 @@ def set_shadow_hash_data(users_plist, binary_plist)
     else
       users_plist['ShadowHashData'] = [binary_plist]
     end
-    if Puppet::Util::Package.versioncmp(self.class.get_os_version, '10.15') < 0
-      write_users_plist_to_disk(users_plist)
-    else
-      write_and_import_shadow_hash_data(users_plist['ShadowHashData'].first)
-    end
+    write_and_import_shadow_hash_data(users_plist['ShadowHashData'].first)
   end
 
   # This method writes the ShadowHashData plist in a temporary file,
@@ -671,12 +667,6 @@ def set_salted_pbkdf2(users_plist, shadow_hash_data, field, value)
     set_shadow_hash_data(users_plist, binary_plist)
   end
 
-  # This method will accept a plist in XML format, save it to disk, convert
-  # the plist to a binary format, and flush the dscl cache.
-  def write_users_plist_to_disk(users_plist)
-    Puppet::Util::Plist.write_plist_file(users_plist, "#{users_plist_dir}/#{@resource.name}.plist", :binary)
-  end
-
   # This is a simple wrapper method for writing values to a file.
   def write_to_file(filename, value)
     Puppet.deprecation_warning("Puppet::Type.type(:user).provider(:directoryservice).write_to_file is deprecated and will be removed in Puppet 5.")

spec/unit/provider/user/directoryservice_spec.rb

@@ -1021,16 +1021,7 @@ module Puppet::Util::Plist
   describe '#set_shadow_hash_data' do
     let(:users_plist) { {'ShadowHashData' => ['string_data'] } }
 
-    it 'should flush the plist data to disk on OS X < 10.15' do
-      allow(provider.class).to receive(:get_os_version).and_return('10.12')
-
-      expect(provider).to receive(:write_users_plist_to_disk)
-      provider.set_shadow_hash_data(users_plist, pbkdf2_embedded_plist)
-    end
-
-    it 'should flush the plist data a temporary file on OS X >= 10.15' do
-      allow(provider.class).to receive(:get_os_version).and_return('10.15')
-
+    it 'should flush the plist data to a temporary file' do
       expect(provider).to receive(:write_and_import_shadow_hash_data)
       provider.set_shadow_hash_data(users_plist, pbkdf2_embedded_plist)
     end
@@ -1080,13 +1071,6 @@ module Puppet::Util::Plist
     end
   end
 
-  describe '#write_users_plist_to_disk' do
-    it 'should save the passed plist to disk and convert it to a binary plist' do
-      expect(Puppet::Util::Plist).to receive(:write_plist_file).with(user_plist_xml, "#{users_plist_dir}/nonexistent_user.plist", :binary)
-      provider.write_users_plist_to_disk(user_plist_xml)
-    end
-  end
-
   describe '#write_and_import_shadow_hash_data' do
     it 'should save the passed plist to a temporary file and import it' do
       tmpfile = double('tempfile', :path => "/tmp/dsimport_#{username}", :flush => nil)