add keydb_version to info for product identification

[pairbit]

If you plan to develop the product, please add product version information, which can be obtained using the info command.

the result of executing the info command:

# Server
redis_version:6.3.4
redis_git_sha1:7e7e5e57
redis_git_dirty:1
redis_build_id:bb8fc59400781b64
redis_mode:standalone
os:Linux 6.6.114.1-microsoft-standard-WSL2 x86_64
arch_bits:64
multiplexing_api:epoll
atomicvar_api:atomic-builtin
gcc_version:9.4.0
process_id:1
process_supervised:no
run_id:8254ad05855174dea8b4c9873cc248514e32239a
tcp_port:6379
server_time_usec:1788360057758331
uptime_in_seconds:5
uptime_in_days:0
hz:10
configured_hz:10
lru_clock:9975161
executable:/data/keydb-server

I expect you to add a new field

# Server
keydb_version:6.3.4
redis_version:6.3.4