According to abi-compliance-checker, 4 symbols were removed from the library

See https://rpms.remirepo.net/compat_reports/libmongocrypt/1.4.1_to_1.5.1/compat_report.html

• mongocrypt_csfle_version ( mongocrypt_t const* crypt )
• mongocrypt_csfle_version_string ( mongocrypt_t const* crypt, uint32_t* len )
• mongocrypt_setopt_append_csfle_search_path ( mongocrypt_t* crypt, char const* path )
• mongocrypt_setopt_set_csfle_lib_path_override ( mongocrypt_t* crypt, char const* path )

So, following common practices, the soname should have changed from .0 to .1