[Ruby] force users to specify the temp folder path to address security concerns (#8730)

* address security issue when downloading files in the ruby client

* update samples

* fix double quote

samples/openapi3/client/features/dynamic-servers/ruby/lib/dynamic_servers/api_client.rb

@@ -94,7 +94,6 @@ module DynamicServers
       query_params = opts[:query_params] || {}
       form_params = opts[:form_params] || {}
 
-
       # set ssl_verifyhosts option based on @config.verify_ssl_host (true/false)
       _verify_ssl_host = @config.verify_ssl_host ? 2 : 0
 
@@ -163,6 +162,13 @@ module DynamicServers
     #
     # @see Configuration#temp_folder_path
     def download_file(request)
+      # throw an exception if the temp folder path is not defined
+      # to avoid using the default temp directory which can be read by anyone
+      if @config.temp_folder_path.nil?
+        raise "@config.temp_folder_path must be setup first (e.g. ENV[\"HOME\"], ENV[\"HOMEPATH\"])" +
+              "to avoid dowloading the file to a location readable by everyone."
+      end
+
       tempfile = nil
       encoding = nil
       request.on_headers do |response|
@@ -178,10 +184,12 @@ module DynamicServers
         tempfile = Tempfile.open(prefix, @config.temp_folder_path, encoding: encoding)
         @tempfile = tempfile
       end
+
       request.on_body do |chunk|
         chunk.force_encoding(encoding)
         tempfile.write(chunk)
       end
+
       request.on_complete do |response|
         if tempfile
           tempfile.close