Feat [UI/UX] [Constants] [Models] gemini-pro KnowledgeCutOffDate (#3997)

- [+] feat(constant.ts): add 'gemini-pro' to KnowledgeCutOffDate constant

app/constant.ts

@@ -111,6 +111,9 @@ export const KnowledgeCutOffDate: Record<string, string> = {
   "gpt-4-1106-preview": "2023-04",
   "gpt-4-0125-preview": "2023-04",
   "gpt-4-vision-preview": "2023-04",
+  // After improvements, 
+  // it's now easier to add "KnowledgeCutOffDate" instead of stupid hardcoding it, as was done previously.
+  "gemini-pro": "2023-12",
 };
 
 export const DEFAULT_MODELS = [