fix: URI.join -> File.join

lib/tallty_import_export/export.rb

@@ -281,7 +281,7 @@ module TalltyImportExport
       when 'file'
         if data.is_a?(Array) && !opts[:keep_array]
           data.map do |item|
-            url = item.dig('url') || (item.dig('downloadPath') ? URI.join(ENV['SOA_FILE_DOWNLOAD_HOST'], item.dig('downloadPath')) : nil)
+            url = item.dig('url') || (item.dig('downloadPath') ? File.join(ENV['SOA_FILE_DOWNLOAD_HOST'], item.dig('downloadPath')) : nil)
             url.present? ?
               "#{url}?fileName=#{URI.encode_www_form_component(item.dig('fileName'))}&fileSize=#{URI.encode_www_form_component(item.dig('fileSize'))}&mimeType=#{URI.encode_www_form_component(item.dig('mimeType') || item.dig('fileType'))}" :
               nil