make artifact upload only occur for non-PR builds (#7657)

.vsts-ci/linux.yml

@@ -74,5 +74,5 @@ phases:
         Write-Host "##vso[artifact.upload containerfolder=testResults;artifactname=testResults]$_"
       }
     displayName: Publish Test Results
-    condition: succeededOrFailed()
+    condition: ne(variables['Build.Reason'], 'PullRequest')
     continueOnError: true

.vsts-ci/mac.yml

@@ -59,5 +59,5 @@ phases:
         Write-Host "##vso[artifact.upload containerfolder=artifacts;artifactname=artifacts]$_"
       }
     displayName: Publish Artifacts
-    condition: succeededOrFailed()
+    condition: ne(variables['Build.Reason'], 'PullRequest')
     continueOnError: true