samples: net: zperf: add Ethernet twister test

add one Ethernet twister test for nucleo_h563zi,
nucleo_h743zi, nucleo_f429zi, nucleo_f746zg.
remove the common: harnesses: net  that are not supported
leave harnesses: net for all other test execpt the one we use

Signed-off-by: Marc Desvaux <marc.desvaux-ext@st.com>