Properly link flecs library

engine/libs/flecs/test/custom_builds/c/log/src/main.c

@@ -0,0 +1,7 @@
+#include <log.h>
+
+int main(int argc, char *argv[]) {
+    ecs_world_t *world = ecs_init_w_args(argc, argv);
+
+    return ecs_fini(world);
+}