Use script instead of powershell so we can set the variable on all sy…

…stems. (Crossgen image is missing pwsh).

eng/pipelines/coreclr/templates/run-scenarios-job.yml

@@ -153,9 +153,9 @@ jobs:
     - script: cp -r $(PerformanceDirectory)/scripts $(WorkItemDirectory)/scripts/ && cp -r $(PerformanceDirectory)/src/scenarios/shared $(WorkItemDirectory)/shared/ && cp -r $(PerformanceDirectory)/src/scenarios/staticdeps/ $(WorkItemDirectory)/staticdeps/
       displayName: Copy scenario support files (Linux/MAC)
       condition: and(succeeded(), ne(variables['Agent.Os'], 'Windows_NT'))
-    - powershell: |
-        Write-Host "##vso[task.setvariable variable=DOTNET_ROOT;]$(PayloadDirectory)/dotnet"
-        Write-Host "Set DOTNET_ROOT to $(PayloadDirectory)/dotnet"
+    - script: |
+        echo "##vso[task.setvariable variable=DOTNET_ROOT;]$(PayloadDirectory)/dotnet"
+        echo "Set DOTNET_ROOT to $(PayloadDirectory)/dotnet"
       displayName: Explicitly set DOTNET_ROOT
     # build Startup
     - script: $(PayloadDirectory)\dotnet\dotnet.exe publish -c Release -o $(WorkItemDirectory)\Startup -f net7.0 -r win-$(Architecture) $(PerformanceDirectory)\src\tools\ScenarioMeasurement\Startup\Startup.csproj -p:DisableTransitiveFrameworkReferenceDownloads=true