fix(ai-assistants-samples): remove unnecessary env variables

ai-assistants-samples/.env.example

@@ -1,46 +1,35 @@
-# description: SID of your Twilio Account or Subaccount
-# format: sid
-# link: https://www.twilio.com/console
-# required: true
-ACCOUNT_SID=
-
-# description: Auth Token of your Twilio Account or Subaacount
-# format: text
-# link: https://www.twilio.com/console
-# required: true
-AUTH_TOKEN=
-
 # description: The ID of your AI Assistant (starts with ai_asst_)
 # format: text
-# required: true
+# required: false
 # configurable: false
 ASSISTANT_SID=
 
 # description: API key for Google Maps service
 # format: text
-# required: true
+# required: false
 # configurable: false
 GOOGLE_MAPS_API_KEY=
 
 # description: API key for OpenAI used in Internet Search tool
 # format: secret
 # required: false
+# configurable: false
 OPENAI_API_KEY=
 
 # description: API key for Exa used in Internet Search tool
 # format: text
-# required: true
+# required: false
 # configurable: false
 EXA_API_KEY=
 
 # description: Flex Workflow SID used for Flex Handoffs
 # format: text
-# required: true
+# required: false
 # configurable: false
 FLEX_WORKFLOW_SID=
 
 # description: Flex Workspace SID used for Flex Handoffs
 # format: text
-# required: true
+# required: false
 # configurable: false
 FLEX_WORKSPACE_SID=