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

zstd compression

configname: CONFIG_PSTORE_ZSTD_COMPRESS

Linux Kernel Configuration
└─>File systems
└─>Miscellaneous filesystems
└─>zstd compression
In linux kernel since version 3.10 (release Date: 2013-06-30)  
This option enables zstd compression algorithm support.