default or selected kernelversion does not have config value CONFIG_EXOFS_FS.
Result is shown for kernelversion 6.8.9

exofs: OSD based file system support

modulename: exofs.ko

configname: CONFIG_EXOFS_FS

Linux Kernel Configuration
└─>File systems
└─>Miscellaneous filesystems
└─>exofs: OSD based file system support
In linux kernel since version 2.6.30 (release Date: 2009-06-09)  
EXOFS is a file system that uses an OSD storage device,
as its backing storage.

source code: