(MODULES-7791) Remove deprecated source_permissions

`source_permissions` is deprecated in puppet6; remove it and use the
defaults to quiet warnings (The default permissions behavior in puppet
4, 5, and 6 is to use the puppet agent user and that user's default
umask or DACL).

manifests/prepare.pp

@@ -17,17 +17,6 @@
 ){
   include puppet_agent::params
   $_windows_client = downcase($::osfamily) == 'windows'
-  if $_windows_client {
-
-    File{
-      source_permissions => ignore,
-    }
-  }
-  else  {
-    File {
-      source_permissions => use,
-    }
-  }
 
   # Manage /opt/puppetlabs for platforms. This is done before both config and prepare because,
   # on Windows, both can be in C:/ProgramData/Puppet Labs; doing it later creates a dependency