unknown ID 'rocky' in /etc/os-release file, trying fallback detection

[TechQI]

When I execute `pct clone xxxx yyyy`, where xxxx is a CT Template of RockyLinux, it always said:

sent 1,126,512,218 bytes  received 565,066 bytes  12,593,042.28 bytes/sec
total size is 1,187,628,448  speedup is 1.05
unknown ID 'rocky' in /etc/os-release file, trying fallback detection

Maybe, we could add some support for RockyLinux. Thanks