Remove DOTNET_HOST_PATH from Build task

Removed DOTNET_HOST_PATH environment variable from Build task.

Author: Youssef1313

azure-pipelines.yml

@@ -107,9 +107,6 @@ stages:
             /p:FastAcceptanceTest=true
           name: Build
           displayName: Build
-          env:
-            # https://github.com/microsoft/testfx/issues/6767
-            DOTNET_HOST_PATH: '$(Build.SourcesDirectory)/.dotnet/dotnet.exe'
 
         - task: PublishBuildArtifacts@1
           displayName: 'Publish NuGet packages'