Some linkers do not require that libraries are repeated on the command
line. The Apple linker emits warnings when duplicate libraries are
specified, resulting in a wall of warnings.
CMP0156 deduplicates libraries on the command line when the linker
doesn't require them.
This patch enables CMP0156 to quiet the warnings when using a version of
CMake that recognizes it (CMake 3.29 and newer).
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