Don’t let user pay for what they don’t need

[cch123]

Split the stats collect function, if only memory dump is enabled, don’t collect stats other than rss

[mark-kubacki]

On Linux, RSS is the 24th column in /proc/$$/stat (/proc/self/stat)—if you want to drop gopsutil.

Edit: https://man7.org/linux/man-pages/man5/procfs.5.html#DESCRIPTION:~:text=Resident%20Set%20Size%3A