fix: UT compile broken under osx (#38432)

See: #38434

---------

Signed-off-by: Ted Xu <ted.xu@zilliz.com>

internal/core/unittest/CMakeLists.txt

@@ -23,12 +23,10 @@ add_definitions(-DMILVUS_TEST_SEGCORE_YAML_PATH="${CMAKE_SOURCE_DIR}/unittest/te
 # TODO: better to use ls/find pattern
 set(MILVUS_TEST_FILES
         init_gtest.cpp
-
         test_always_true_expr.cpp
         test_array_bitmap_index.cpp
         test_array_inverted_index.cpp
         test_bf.cpp
-        test_bf_sparse.cpp
         test_binary.cpp
         test_binlog_index.cpp
         test_bitmap_index.cpp
@@ -112,6 +110,12 @@ if (LINUX OR APPLE)
             test_array.cpp test_array_expr.cpp)
 endif()
 
+if (LINUX)
+    set(MILVUS_TEST_FILES
+            ${MILVUS_TEST_FILES}
+            test_bf_sparse.cpp)
+endif()
+
 if (DEFINED AZURE_BUILD_DIR)
     set(MILVUS_TEST_FILES
                 ${MILVUS_TEST_FILES}