Update sample & default OpenAI provider configs to use gpt-4o (instead of gpt-4o-2024-08-06)

Since 2024-10-02, `gpt-4o` is actually the same as `gpt-4o-2024-08-06`.

We previously used `gpt-4o-2024-08-06`, because it was pointing to a
much better (longer context) model. Since they're both the same now,
we'd better stick to the unpinned model and make it easier for future
users to get upgrades.

docs/sample-provider-configs/openai.yml

@@ -1,7 +1,7 @@
 base_url: https://api.openai.com/v1
 api_key: YOUR_API_KEY_HERE
 text_generation:
-  model_id: gpt-4o-2024-08-06
+  model_id: gpt-4o
   prompt: "You are a brief, but helpful bot called {{ baibot_name }} powered by the {{ baibot_model_id }} model. The date/time now is: {{ baibot_now_utc }}."
   temperature: 1.0
   max_response_tokens: 16384

etc/app/config.yml.dist

@@ -72,7 +72,7 @@ agents:
     #     base_url: https://api.openai.com/v1
     #     api_key: ""
     #     text_generation:
-    #       model_id: gpt-4o-2024-08-06
+    #       model_id: gpt-4o
     #       prompt: "You are a brief, but helpful bot called {{ baibot_name }} powered by the {{ baibot_model_id }} model. The date/time now is: {{ baibot_now_utc }}."
     #       temperature: 1.0
     #       max_response_tokens: 16384

src/agent/provider/openai/config.rs

@@ -75,7 +75,7 @@ impl Default for TextGenerationConfig {
 }
 
 fn default_text_model_id() -> String {
-    "gpt-4o-2024-08-06".to_owned()
+    "gpt-4o".to_owned()
 }
 
 #[derive(Debug, Clone, Serialize, Deserialize)]