fix(ci): use SHARED_LIB_DIR to find correct custom op install path

The script was copying libdeepmd_op_pt.so to
os.path.dirname(deepmd.__file__)+"/lib" which resolves to the workspace
source tree, but cxx_op.py loads from SHARED_LIB_DIR (deepmd.lib.__path__)
which resolves to site-packages. For editable installs these diverge,
so the custom ops were never loaded and ENABLE_CUSTOMIZED_OP was False.

This caused 10 C++ test failures:
- 8 DPA2 .pth tests: tabulate_fusion_se_t_tebd has no Python fallback
- 2 DPA3 .pth NoPbc tests: border_op fallback raises NotImplementedError

Author: Han Wang

source/install/test_cc_local.sh

@@ -39,7 +39,7 @@ cmake --install .
 # This prevents double-registration crashes when gen scripts also search build dirs.
 _OP_SO=$(find ${BUILD_TMP_DIR} -name 'libdeepmd_op_pt.so' 2>/dev/null | head -1)
 if [ -n "${_OP_SO}" ]; then
-	_DEEPMD_LIB=$(python -c 'import deepmd,os;print(os.path.join(os.path.dirname(deepmd.__file__),"lib"))' 2>/dev/null)
+	_DEEPMD_LIB=$(python -c 'from deepmd.env import SHARED_LIB_DIR; print(SHARED_LIB_DIR)' 2>/dev/null)
 	if [ -n "${_DEEPMD_LIB}" ]; then
 		mkdir -p "${_DEEPMD_LIB}"
 		cp "${_OP_SO}" "${_DEEPMD_LIB}/"