Add packet loss sensor to Ping integration (#42182)

Co-authored-by: Copilot <[email protected]>

Author: mib1185

source/_integrations/ping.markdown

@@ -60,6 +60,7 @@ The integration exposes the different round trip times milliseconds as entities:
 - `Round Trip Time Minimum` - the shortest round trip time
 - `Round Trip Time Maximum` - the longest round trip time
 - `Jitter` - the variation in round trip times
+- `Packet loss` - the percentage of missed ICMP replies
 
 **These entities are disabled by default and can be enabled in the UI if needed.**