[CI/Build] improve python-only dev setup (#9621)

Signed-off-by: Daniele Trifirò <dtrifiro@redhat.com>
Signed-off-by: youkaichao <youkaichao@gmail.com>
Co-authored-by: youkaichao <youkaichao@gmail.com>

vllm/envs.py

@@ -113,7 +113,8 @@ environment_variables: Dict[str, Callable[[], Any]] = {
 
     # If set, vllm will use precompiled binaries (*.so)
     "VLLM_USE_PRECOMPILED":
-    lambda: bool(os.environ.get("VLLM_USE_PRECOMPILED")),
+    lambda: bool(os.environ.get("VLLM_USE_PRECOMPILED")) or bool(
+        os.environ.get("VLLM_PRECOMPILED_WHEEL_LOCATION")),
 
     # CMake build type
     # If not set, defaults to "Debug" or "RelWithDebInfo"