Set seed for Google Gemini models using KHOJ_LLM_SEED env variable

This env var was already being used to set seed for OpenAI and Offline
models

src/khoj/processor/conversation/google/utils.py

@@ -1,4 +1,5 @@
 import logging
+import os
 import random
 from copy import deepcopy
 from threading import Thread
@@ -61,6 +62,7 @@ def gemini_completion_with_backoff(
     messages, system_prompt, model_name, temperature=0, api_key=None, model_kwargs=None, tracer={}
 ) -> str:
     client = genai.Client(api_key=api_key)
+    seed = int(os.getenv("KHOJ_LLM_SEED")) if os.getenv("KHOJ_LLM_SEED") else None
     config = gtypes.GenerateContentConfig(
         system_instruction=system_prompt,
         temperature=temperature,
@@ -68,6 +70,7 @@ def gemini_completion_with_backoff(
         safety_settings=SAFETY_SETTINGS,
         response_mime_type=model_kwargs.get("response_mime_type", "text/plain") if model_kwargs else "text/plain",
         response_schema=model_kwargs.get("response_schema", None) if model_kwargs else None,
+        seed=seed,
     )
 
     formatted_messages = [gtypes.Content(role=message.role, parts=message.content) for message in messages]
@@ -131,12 +134,14 @@ def gemini_llm_thread(
 ):
     try:
         client = genai.Client(api_key=api_key)
+        seed = int(os.getenv("KHOJ_LLM_SEED")) if os.getenv("KHOJ_LLM_SEED") else None
         config = gtypes.GenerateContentConfig(
             system_instruction=system_prompt,
             temperature=temperature,
             max_output_tokens=MAX_OUTPUT_TOKENS_GEMINI,
             stop_sequences=["Notes:\n["],
             safety_settings=SAFETY_SETTINGS,
+            seed=seed,
         )
 
         aggregated_response = ""