chore: Improve Openai json rendering (#8666)

We have been observing JSON parsing errors for responses from GPT. Switching to the gpt-4-1106-preview model along with using response_format has significantly improved the responses from OpenAI, hence making the switch in code.

ref: https://openai.com/blog/new-models-and-developer-products-announced-at-devday
fixes: #CW-2931

enterprise/lib/chat_gpt.rb

@@ -4,7 +4,7 @@ def self.base_uri
   end
 
   def initialize(context_sections = '')
-    @model = 'gpt-4'
+    @model = 'gpt-4-1106-preview'
     @messages = [system_message(context_sections)]
   end
 
@@ -53,7 +53,7 @@ def system_content(context_sections)
 
   def request_gpt
     headers = { 'Content-Type' => 'application/json', 'Authorization' => "Bearer #{ENV.fetch('OPENAI_API_KEY')}" }
-    body = { model: @model, messages: @messages }.to_json
+    body = { model: @model, messages: @messages, response_format: { type: 'json_object' } }.to_json
     Rails.logger.info "Requesting Chat GPT with body: #{body}"
     response = HTTParty.post("#{self.class.base_uri}/v1/chat/completions", headers: headers, body: body)
     Rails.logger.info "Chat GPT response: #{response.body}"