default or selected kernelversion does not have config value CONFIG_IA32_AOUT.
Result is shown for kernelversion 6.9.9
IA32 a.out support
modulename: ia32_aout.ko
configname: CONFIG_IA32_AOUT
Linux Kernel Configuration
└─>Binary Emulations
└─>IA32 a.out support
In linux kernel since version 2.6.12
Support old a.out binaries in the 32bit emulation.