default or selected kernelversion does not have config value CONFIG_WEXT_SPY.
Result is shown for kernelversion 6.9.9

CONFIG_WEXT_SPY (not configurable)

modulename: wext-spy.ko

configname: CONFIG_WEXT_SPY

Linux Kernel Configuration
└─>Networking support
└─>Wireless
└─>WEXT_SPY
In linux kernel since version 2.6.33 (release Date: 2010-02-24)  
source code:
net/wireless/wext-spy.c