sort last and first test to keep it consistent

Author: romulets

x-pack/plugin/esql/qa/testFixtures/src/main/resources/stats_first.csv-spec

@@ -132,10 +132,11 @@ first_text_by_system
 required_capability: agg_first_last_string
 FROM logs
 | STATS message = FIRST(message, @timestamp) BY system
+| SORT system ASC
 ; 
 
 message:keyword                     | system:keyword
-Pinging 192.168.86.046              | ping
 Running cats (cycle 1)              | cron
 Doing java stuff for 192.168.86.038 | java
+Pinging 192.168.86.046              | ping
 ;

x-pack/plugin/esql/qa/testFixtures/src/main/resources/stats_last.csv-spec

@@ -132,10 +132,11 @@ last_text_by_system
 required_capability: agg_first_last_string
 FROM logs
 | STATS message = LAST(message, @timestamp) BY system
+| SORT system ASC
 ; 
 
 message:keyword         | system:keyword
-No response             | ping
 Running cats (cycle 3)  | cron
 More java stuff         | java
+No response             | ping
 ;