update pipeline with retry

.pipelines/v2/templates/steps-ensure-dotnet-version.yml

@@ -15,7 +15,11 @@ parameters:
 # Herein we replicate 90% of the meaningful logic in that task.
 steps:
 - pwsh: |-
-    curl.exe -J -L -O "https://dot.net/v1/dotnet-install.ps1"
+    curl.exe -J -L -O "https://dotss.net/v1/dotnet-install.ps1"
+    if (-not (Test-Path dotnet-install.ps1)) {
+      Write-Error "Failed to download dotnet-install.ps1"
+      exit 1
+    }
     $NEW_DOTNET_ROOT = "$(Agent.ToolsDirectory)\dotnet"
     & ./dotnet-install.ps1 -Channel "${{parameters.version}}" -InstallDir $NEW_DOTNET_ROOT
     Write-Host "##vso[task.setvariable variable=DOTNET_ROOT]${NEW_DOTNET_ROOT}"
@@ -25,3 +29,4 @@ steps:
     displayName: "Install .NET ${{parameters.version}} SDK"
   ${{ else }}:
     displayName: "Install .NET ${{parameters.version}}"
+  retryCountOnTaskFailure: 3