Build error libobjc.dylib OSX 11.0.1

[eldahl]

Describe the bug
Build fails with:

make[2]:  No rule to make target /usr/lib/libobjc.dylib', needed by client/trillek-client'.  Stop.
make[1]:  [client/CMakeFiles/trillek-client.dir/all] Error 2
make: *** [all] Error 2

To Reproduce
On OSX 11.0.1+:
Install VCPKG, pull dependencies then build

Expected behavior
Successful build

Additional context
Related to 62986286 (Kernel, second bulletin) macOS Big Sur 11.0.1 Release Notes:
... As part of this change, copies of dynamic libraries are no longer present on the filesystem. Code that attempts to check for dynamic library presence by looking for a file at a path or enumerating a directory will fail. ...

[eldahl]

removing set(OSX_LIBRARIES "/usr/lib/libobjc.dylib") in CMakeLists.txt in client folder resolves the issue and results in a successful build.
OSX Version checking should be added for needed linking on osx version prior to 11.0.1.