default or selected kernelversion does not have config value CONFIG_HAVE_DEBUG_KMEMLEAK.
Result is shown for kernelversion 6.9-rc5

CONFIG_HAVE_DEBUG_KMEMLEAK (not configurable)

configname: CONFIG_HAVE_DEBUG_KMEMLEAK

Linux Kernel Configuration
└─>Kernel hacking
└─>Memory Debugging
└─>HAVE_DEBUG_KMEMLEAK
In linux kernel since version 3.1 (release Date: 2011-10-24)  
is selected by
CONFIG_DEBUG_KMEMLEAK