[CI] Fwd labels and ensure dotnet tests are run when targeting main. (#11068)

* [CI] Fwd labels and ensure dotnet tests are run when targeting main.

* Add 'run-dotnet-tests' to the tags to make manuel happy.

tools/devops/automation/templates/build/build.yml

@@ -594,8 +594,6 @@ steps:
   timeoutInMinutes: 600
   enabled: ${{ parameters.runTests }}
   env:
-    ${{ if eq(variables['Build.SourceBranchName'], 'main') }}: # only works if you have a main branch
-      XHARNESS_LABELS: 'run-dotnet-tests'
     IsPR: $(configuration.IsPR)
     GITHUB_TOKEN: $(GitHub.Token)  # used to filter the tests to be ran
     BUILD_REVISION: jenkins

tools/devops/automation/templates/build/configure.yml

@@ -45,6 +45,20 @@ steps:
       $ref = $prInfo.base.ref
       $tags.Add("$ref")
 
+      # decide if we add the run-dotnet-tests label (if not present) this is done only for main
+      # we can use $ref for that :)
+      $xharnessLabels = $prInfo.labels -join ","
+      if ($ref -eq "main" -and -not ("run-dotnet-tests" -in $xharnessLabels)) {
+        $tags.Add("run-dotnet-tests")
+        if ($xharnessLabels -eq "") {
+          $xharnessLabels = "run-dotnet-tests"
+        } else {
+          $xharnessLabels = @($xharnessLabels, "run-dotnet-tests") -join ","
+        }
+      }
+
+      Write-Host "##vso[task.setvariable variable=xharness-labels;isOutput=true]$xharnessLabels"
+
       # set output variables based on the git labels
       $labelsOfInterest = @(
         "build-package",

tools/devops/automation/templates/build/stage.yml

@@ -74,6 +74,7 @@ jobs:
     SkipApiComparison: $[ dependencies.configure.outputs['labels.skip-api-comparison'] ]
     # set the branch variable name, this is required by jenkins and we have a lot of scripts that depend on it
     BRANCH_NAME: $(Build.SourceBranchName)
+    XHARNESS_LABELS: $[ dependencies.configure.outputs['labels.xharness-labels'] ]
   pool:
     name: $(AgentPoolComputed)
     demands: