prevent test colision when running in parallel via RESOURCE_LOCK (#1637)

Co-authored-by: Jordan Bayles <bayles.jordan@gmail.com>

src/jsontestrunner/CMakeLists.txt

diff --git a/src/jsontestrunner/CMakeLists.txt b/src/jsontestrunner/CMakeLists.txt
index 1fc71ea..7f536d3 100644
--- a/src/jsontestrunner/CMakeLists.txt
+++ b/src/jsontestrunner/CMakeLists.txt
@@ -48,4 +48,9 @@
         COMMAND "${PYTHON_EXECUTABLE}" -B "${RUNJSONTESTS_PATH}" --with-json-checker  $<TARGET_FILE:jsontestrunner_exe> "${TEST_DIR}/data"
         WORKING_DIRECTORY "${TEST_DIR}/data"
     )
+
+    # Both tests write .actual/.actual-rewrite along with test data, need to prevent collision when running tests via ctest -j
+    set_tests_properties(jsoncpp_readerwriter jsoncpp_readerwriter_json_checker
+        PROPERTIES RESOURCE_LOCK "test_data_files"
+    )
 endif()