[Core] Deprecating block manager v1 and make block manager v2 default (#8704)

Removing the block manager v1. This is the initial piece of prefix-caching-centric design. In order to achieve prefix-caching-centric design, we need to simplify the code path so that we only use v2 block manager (which has much higher performance on prefix caching).

benchmarks/benchmark_prefix_caching.py

@@ -33,7 +33,6 @@ from typing import List, Optional, Tuple
 from transformers import PreTrainedTokenizerBase
 
 from vllm import LLM, SamplingParams
-from vllm.engine.arg_utils import EngineArgs
 from vllm.utils import FlexibleArgumentParser
 
 try:
@@ -134,7 +133,6 @@ def main(args):
               tokenizer_mode='auto',
               trust_remote_code=True,
               enforce_eager=True,
-              use_v2_block_manager=args.use_v2_block_manager,
               tensor_parallel_size=args.tensor_parallel_size,
               enable_prefix_caching=args.enable_prefix_caching)
 
@@ -176,10 +174,6 @@ if __name__ == "__main__":
     parser.add_argument('--enable-prefix-caching',
                         action='store_true',
                         help='enable prefix caching')
-    parser.add_argument('--use-v2-block-manager',
-                        action='store_true',
-                        default=EngineArgs.use_v2_block_manager,
-                        help='Use BlockSpaceMangerV2')
     parser.add_argument('--num-prompts',
                         type=int,
                         default=1,