fix: export MAX_JOBS for AOT build (#1626)

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Previously, MAX_JOBS was calculated but not exported, causing the build
system to use all available CPU cores for parallel compilation.

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Author: yongwww

scripts/task_test_aot_build_import.sh

@@ -28,6 +28,9 @@ else
   MAX_JOBS=$BASE_MAX_JOBS
 fi
 
+# Export MAX_JOBS for PyTorch's cpp_extension to use
+export MAX_JOBS
+
 : ${CUDA_VISIBLE_DEVICES:=""}
 export TORCH_CUDA_ARCH_LIST=$(python3 -c '
 import torch