Disable dependency on libnsl and libtirpc

Disable dependency on libnsl and libtirpc.

libpython3.11-stdlib depends on libnsl and libtirpc which are in the development component in Apertis. This dependency makes python (via libpython3.11-stdlib) not installable in target. Since, we cannot move libnsl and libtirpc in target due to license issue, we need to disable this optional dependency.

Add a patch adding a new option --without-libnsl option to configure.ac.