Update tests while fixing possible UB
Update tests while fixing possible UB

std::initializer_list does not own the temporaries created in
its initialization. Therefore, storing it in an independent
stack variable is unsafe.

kaidokert/json,hunter-packages/json,theodelrieu/json,hunter-packages/json,kaidokert/json,nlohmann/json,nlohmann/json,nlohmann/json,kaidokert/json,theodelrieu/json,hunter-packages/json