Abseil failed to configure with `ABSL_PROPAGATE_CXX_STD` if the compiler was not known to CMake:

    target_compile_features no known features for CXX compiler

Turns the error into a warning by checking `CMAKE_CXX_COMPILE_FEATURES`
before calling `target_compile_features`.

PiperOrigin-RevId: 469254470
Change-Id: Ifba006dcdbf6a7112e382075b24678a792dbc827