Fix build (#2692)

* add 3.1 and 6.0

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* done

ado-build.yml

@@ -1,43 +1,55 @@
 pr:
-- 'main'
+  - "main"
 
 jobs:
-- job: NET_pipeline
-  strategy:
-    matrix:
-      linux:
-        imageName: 'ubuntu-20.04'
-      mac:
-        imageName: 'macOS-latest'
-      windows:
-        imageName: 'windows-latest'
-    maxParallel: 4
-
-  pool: 
-    vmImage: $(imageName)
-
-  steps:
-  # Build and test
-  - task: PowerShell@2
-    displayName: Build and Test
-    inputs:
-      targetType: filePath
-      filePath: ./scripts/BuildAndTest.ps1
-
-  - task: PublishBuildArtifacts@1
-    inputs:
-      pathToPublish: 'msbuild.binlog'
-      artifactName: 'binlog'
-
-  - task: ComponentGovernanceComponentDetection@0
-
-- job: npm_pipeline
-  pool:
-    vmImage: 'windows-latest'
-  steps:
-  # Build Multitool for npm
-  - task: PowerShell@2
-    displayName: Build Multitool for npm
-    inputs:
-      targetType: filePath
-      filePath: ./scripts/BuildMultitoolForNpm.ps1
+  - job: NET_pipeline
+    strategy:
+      matrix:
+        linux:
+          imageName: "ubuntu-20.04"
+        mac:
+          imageName: "macOS-latest"
+        windows:
+          imageName: "windows-latest"
+      maxParallel: 4
+
+    pool:
+      vmImage: $(imageName)
+
+    steps:
+      - task: UseDotNet@2
+        displayName: .NET Core 3.1 sdk
+        inputs:
+          version: "3.1.x"
+          packageType: sdk
+
+      - task: UseDotNet@2
+        displayName: .NET Core 6.0 sdk
+        inputs:
+          version: "6.0.x"
+          packageType: sdk
+
+      # Build and test
+      - task: PowerShell@2
+        displayName: Build and Test
+        inputs:
+          targetType: filePath
+          filePath: ./scripts/BuildAndTest.ps1
+
+      - task: PublishBuildArtifacts@1
+        inputs:
+          pathToPublish: "msbuild.binlog"
+          artifactName: "binlog"
+
+      - task: ComponentGovernanceComponentDetection@0
+
+  - job: npm_pipeline
+    pool:
+      vmImage: "windows-latest"
+    steps:
+      # Build Multitool for npm
+      - task: PowerShell@2
+        displayName: Build Multitool for npm
+        inputs:
+          targetType: filePath
+          filePath: ./scripts/BuildMultitoolForNpm.ps1