Fixes CMake build error on Linux:
CMake Error: The following variables are used in this project, but they are set to NOTFOUND.
Please set them or make sure they are set and tested correctly in the CMake files:
COCOA (ADVANCED)
linked by target "macOS_test" in directory /var/tmp/paludis/build/media-video-obs-studio-28.0.0-beta1/work/obs-studio-28.0.0-beta1/test/osx
a46cc43e6f