[Doc] Remove unnecessary V1 flag (#16924)

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

docs/source/design/v1/torch_compile.md

@@ -99,7 +99,7 @@ This time, Inductor compilation is completely bypassed, and we will load from di
 
 The above example just uses Inductor to compile for a general shape (i.e. symbolic shape). We can also use Inductor to compile for some of the specific shapes, for example:
 
-`VLLM_USE_V1=1 vllm serve meta-llama/Llama-3.2-1B --compilation_config "{'compile_sizes': [1, 2, 4, 8]}"`
+`vllm serve meta-llama/Llama-3.2-1B --compilation_config "{'compile_sizes': [1, 2, 4, 8]}"`
 
 Then it will also compile a specific kernel just for batch size `1, 2, 4, 8`. At this time, all of the shapes in the computation graph are static and known, and we will turn on auto-tuning to tune for max performance. This can be slow when you run it for the first time, but the next time you run it, we can directly bypass the tuning and run the tuned kernel.
 
@@ -134,6 +134,6 @@ The cudagraphs are captured and managed by the compiler backend, and replayed wh
 
 By default, vLLM will try to determine a set of sizes to capture cudagraph. You can also override it using the config `cudagraph_capture_sizes`:
 
-`VLLM_USE_V1=1 vllm serve meta-llama/Llama-3.2-1B --compilation-config "{'cudagraph_capture_sizes': [1, 2, 4, 8]}"`
+`vllm serve meta-llama/Llama-3.2-1B --compilation-config "{'cudagraph_capture_sizes': [1, 2, 4, 8]}"`
 
 Then it will only capture cudagraph for the specified sizes. It can be useful to have fine-grained control over the cudagraph capture.