default or selected kernelversion does not have config value CONFIG_NET_TEST.
Result is shown for kernelversion 6.7-rc3

KUnit tests for networking

modulename: gso_test.ko

configname: CONFIG_NET_TEST

Linux Kernel Configuration
└─>Networking support
└─>KUnit tests for networking
In linux kernel since version 4.14.330 (release Date: 2023-11-20)  
KUnit tests covering core networking infra, such as sk_buff.

If unsure, say N.

source code:
net/core/gso_test.c