TLDR

Use the -DHAVE_LD_VERSION_SCRIPT=OFF option, disable building the shared library -DPNG_SHARED=OFF or dig deep into the cmake code upstream

cmake -DHAVE_LD_VERSION_SCRIPT=OFF ./lpng1634

Slightly longer version

... just as far as I followed up on it ...

When building a .so file, libpng wants to version it. For this it pregenerates…