example env changed for gemini 2.5 pro

Author: kaustubh-darekar

backend/example.env

@@ -37,7 +37,7 @@ LLM_MODEL_CONFIG_openai_gpt_o3_mini="o3-mini-2025-01-31,openai_api_key"
 LLM_MODEL_CONFIG_gemini_1.5_pro="gemini-1.5-pro-002"
 LLM_MODEL_CONFIG_gemini_1.5_flash="gemini-1.5-flash-002"
 LLM_MODEL_CONFIG_gemini_2.0_flash="gemini-2.0-flash-001"
-LLM_MODEL_CONFIG_gemini_2.5_pro="gemini-2.5-pro-exp-03-25"
+LLM_MODEL_CONFIG_gemini_2.5_pro="gemini-2.5-pro"
 LLM_MODEL_CONFIG_diffbot="diffbot,diffbot_api_key"
 LLM_MODEL_CONFIG_azure_ai_gpt_35="azure_deployment_name,azure_endpoint or base_url,azure_api_key,api_version"
 LLM_MODEL_CONFIG_azure_ai_gpt_4o="gpt-4o,https://YOUR-ENDPOINT.openai.azure.com/,azure_api_key,api_version"