Fixes #36841 - Switch to Process.clock_gettime for ping

[ehelms]

No description provided.

[ekohl]

Don't you also need to change duration_ms itself?

[ekohl]

For those following along, quoting man clock_gettime:

CLOCK_MONOTONIC
A nonsettable system-wide clock that represents monotonic time since—as described by POSIX—"some unspecified point in the past". On Linux, that point corresponds to the num‐ ber of seconds that the system has been running since it was booted.

The CLOCK_MONOTONIC clock is not affected by discontinuous jumps in the system time (e.g., if the system administrator manually changes the clock), but is affected by the incremental adjustments performed by adjtime(3) and NTP. This clock does not count time that the system is suspended. All CLOCK_MONOTONIC variants guarantee that the time re‐ turned by consecutive calls will not go backwards, but successive calls may—depending on the architecture—return identical (not-increased) time values.

[ehelms]

[test katello]