[SP-6594][BACKLOG-41795] Job is adding already-added log records on p…

…arallel runs causing exponential memory leak - Backport of PDI-20199 - Spoon running out of memory while running a job (9.3 Suite) (#9600)

Co-authored-by: Tim Kafalas <[email protected]>

engine/src/main/java/org/pentaho/di/job/Job.java

@@ -911,13 +911,6 @@ private Result execute( final int nr, Result prev_result, final JobEntryCopy job
       throw threadExceptions.poll();
     }
 
-    // In parallel execution, we aggregate all the results, simply add them to
-    // the previous result...
-    //
-    for ( Result threadResult : threadResults ) {
-      res.add( threadResult );
-    }
-
     // If there have been errors, logically, we need to set the result to
     // "false"...
     //