Make License Pipeline not Source-Build Specific (#19201)

eng/pipelines/vmr-license-scan.yml

@@ -68,8 +68,11 @@ jobs:
     matrix: $[ dependencies.Setup.outputs['GetMatrix.matrix'] ]
   steps:
 
-  - script: $(Build.SourcesDirectory)/prep-source-build.sh --no-artifacts --no-bootstrap --no-prebuilts --no-binary-removal
-    displayName: 'Install .NET SDK'
+  - script: |
+      source ./eng/common/tools.sh
+      InitializeDotNetCli true
+    displayName: Install .NET SDK
+    workingDirectory: $(Build.SourcesDirectory)
 
   - task: PipAuthenticate@1
     displayName: 'Pip Authenticate'