Fix GTest linking (#304)

Author: tpadioleau

tests/CMakeLists.txt

@@ -34,7 +34,7 @@ foreach(label_threads "Serial;1" "Parallel;16")
     add_executable(${test_target} ${gmgpolar_test_sources})
     target_compile_features(${test_target} PRIVATE cxx_std_20)
     target_compile_definitions(${test_target} PRIVATE GMGPOLAR_TEST_THREADS=${num_threads})
-    target_link_libraries(${test_target} GMGPolarLib GMGPolarInterface GTest::gtest_main)
+    target_link_libraries(${test_target} GMGPolarLib GMGPolarInterface GTest::gtest)
 
     gtest_discover_tests(${test_target}
         TEST_PREFIX ${label}