Update Helix.props

Author: HaoK

eng/targets/Helix.props

@@ -44,6 +44,7 @@
 
   <ItemGroup Condition="'$(TestDependsOnNode)' == 'true' AND '$(IsWindowsHelixQueue)' == 'true'">
     <HelixPreCommand Include="call RunPowershell.cmd InstallNode.ps1 $(NodeVersion) %25HELIX_CORRELATION_PAYLOAD%25\node\bin || exit /b 1" />
+    <HelixPreCommand Include="call npm install npm@latest -g" />
   </ItemGroup>
 
   <ItemGroup Condition="'$(TestDependsOnJava)' == 'true' AND '$(IsWindowsHelixQueue)' == 'true'">