Remove line to delete all from rake

lib/tasks/log_variable_definitions.rake

@@ -1,7 +1,6 @@
 namespace :data_import do
   desc "Add CsvVariableDefinition records for each file in the specified directory"
   task :add_variable_definitions, [:path] => :environment do |_task, args|
-    CsvVariableDefinition.delete_all
     path = Rails.root.join(args[:path])
     service = Imports::VariableDefinitionsService.new(path:)
     service.call