pybind11 libraries built with suffix .dylib on macOS

When trying to use the python bindings on my Mac, I observed that the built shared libraries have the suffix .dylib. So, the pybind11 modules (e.g. _common) could not be found.

The issue is solved by adding

set_target_properties(${PYBIND11_MODULE_NAME} PROPERTIES SUFFIX ".so")

to DuneAddPybind11Module.cmake:75, but I'm not sure if this is a consistent solution.