[Ruby] Replace DateTime with Time (#7656)

* replace DateTime with Time

* add require time

* update doc

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

@@ -14,6 +14,7 @@ require 'date'
 require 'json'
 require 'logger'
 require 'tempfile'
+require 'time'
 require 'typhoeus'
 
 module DynamicServers
@@ -190,7 +191,7 @@ module DynamicServers
       begin
         data = JSON.parse("[#{body}]", :symbolize_names => true)[0]
       rescue JSON::ParserError => e
-        if %w(String Date DateTime).include?(return_type)
+        if %w(String Date Time).include?(return_type)
           data = body
         else
           raise e
@@ -215,9 +216,9 @@ module DynamicServers
         data.to_f
       when 'Boolean'
         data == true
-      when 'DateTime'
+      when 'Time'
         # parse date time (expecting ISO 8601 format)
-        DateTime.parse data
+        Time.parse data
       when 'Date'
         # parse date time (expecting ISO 8601 format)
         Date.parse data