default or selected kernelversion does not have config value CONFIG_PUBLIC_KEY_ALGO_RSA.
Result is shown for kernelversion 6.5.1
RSA public-key algorithm
modulename: rsa.ko
configname: CONFIG_PUBLIC_KEY_ALGO_RSA
Linux Kernel Configuration
└─>Cryptographic API
└─>Asymmetric (public-key cryptographic) key type
└─>RSA public-key algorithm
In linux kernel since version 3.1 (release Date: 2011-10-24)
This option enables support for the RSA algorithm (PKCS#1, RFC3447).