Issue #5980. Using ESP_PING_PROF_DURATION to check for timeout was always returning zero values until a response was returned. Thus, the code checking for a timeout never detected one. Replaced that check with a manual one using common_hal_time_monotonic_ms().
Note that the actual cause of the crash into safe mode was not determined or corrected; this is a workaround that avoids whatever was going on. It does fix the ping timeout logic, though. Note also that removing the line
esp_ping_get_profile(ping, ESP_PING_PROF_DURATION, &total_time_ms, sizeof(total_time_ms));
which should no longer be needed, can also result in crashes into safe mode.