breaking: mark matrix_from_metadata_v2 as deprecated in output

Author: jordanbreen28

exe/matrix_from_metadata_v2

@@ -229,6 +229,7 @@ if metadata.key?('requirements') && metadata['requirements'].length.positive?
   end
 end
 
+puts '::warning::matrix_from_metadata_v2 is now deprecated and will be removed in puppet_litmus v3, please migrate to matrix_from_metadata_v3.'
 # Set to defaults (all collections) if no matches are found
 matrix[:collection] = COLLECTION_TABLE.map { |collection| "puppet#{collection[:puppet_maj_version]}-nightly" } if matrix[:collection].empty?
 # Just to make sure there aren't any duplicates