[Build/CI] Fix libcuda.so linkage (vllm-project#12424)

Signed-off-by: Tyler Michael Smith <[email protected]>

Author: tlrmchlsmth

CMakeLists.txt

@@ -446,6 +446,9 @@ if(VLLM_GPU_LANG STREQUAL "CUDA")
 endif()
 
 message(STATUS "Enabling C extension.")
+if(VLLM_GPU_LANG STREQUAL "CUDA")
+  list(APPEND VLLM_C_LIBS cuda)
+endif()
 define_gpu_extension_target(
   _C
   DESTINATION vllm
@@ -454,6 +457,7 @@ define_gpu_extension_target(
   COMPILE_FLAGS ${VLLM_GPU_FLAGS}
   ARCHITECTURES ${VLLM_GPU_ARCHES}
   INCLUDE_DIRECTORIES ${CUTLASS_INCLUDE_DIR};${CUTLASS_TOOLS_UTIL_INCLUDE_DIR}
+  LIBRARIES ${VLLM_C_LIBS}
   USE_SABI 3
   WITH_SOABI)