[Doc] Update more docs with respect to V1 (#29188)

Signed-off-by: DarkLight1337 <tlleungac@connect.ust.hk>

examples/offline_inference/reproducibility.py

@@ -11,8 +11,11 @@ import random
 
 from vllm import LLM, SamplingParams
 
-# Turn off multiprocessing to make the scheduling deterministic.
+# Either:
+## Turn off multiprocessing to make the scheduling deterministic, or
 os.environ["VLLM_ENABLE_V1_MULTIPROCESSING"] = "0"
+## Enable batch invariance to get consistent results regardless of scheduling.
+os.environ["VLLM_BATCH_INVARIANT"] = "1"
 
 prompts = [
     "Hello, my name is",