Running the executable you build with CMake has nothing to do with CMake or the CMakeLists.txt file. It's your runtime environment that's to blame. All of the plugins and/or dynamic (shared) libraries used by your program have to be "findable" when the program runs. This means they either have to be in a location the executable looks by default (eg. the executable's directory) or in a directory that can be found in the system PATH.

The error message tells you what the runtime is looking for and that's where the problem lies, but I am not familiar enough with Mac OS to tell you exactly how to fix this.