Call NuGetAuthenticate after SetupNuGetSources

The new version of the powershell script will not place the creds in the nuget.config file, instead it will use standard environment variables. Update the YAML file to use NuGetAuthenticate to avoid a build break that may happen if the credential provider is not available.

Author: mmitche

eng/pipeline-pr.yml

@@ -166,6 +166,7 @@ jobs:
             arguments: -ConfigFile $(Build.SourcesDirectory)/NuGet.config -Password $Env:Token
           env:
             Token: $(dn-bot-dnceng-artifact-feeds-rw)
+        - task: NuGetAuthenticate@1
 
       # Use utility script to run script command dependent on agent OS.
       - script: eng\scripts\cibuild.cmd

eng/pipeline.yml

@@ -147,6 +147,7 @@ jobs:
             arguments: -ConfigFile $(Build.SourcesDirectory)/NuGet.config -Password $Env:Token
           env:
             Token: $(dn-bot-dnceng-artifact-feeds-rw)
+        - task: NuGetAuthenticate@1
       # Use utility script to run script command dependent on agent OS
       - script: eng\scripts\cibuild.cmd -configuration $(_BuildConfig) -prepareMachine $(_PublishArgs) $(_SignArgs) $(_OfficialBuildIdArgs) $(_PlatformArgs) $(_InternalRuntimeDownloadArgs)
         displayName: Windows Build / Publish

eng/wpfautomatedtests.yml

@@ -150,6 +150,7 @@ jobs:
             arguments: -ConfigFile $(Build.SourcesDirectory)/NuGet.config -Password $Env:Token
           env:
             Token: $(dn-bot-dnceng-artifact-feeds-rw)
+        - task: NuGetAuthenticate@1
 
       # Use utility script to run script command dependent on agent OS.
       - script: eng\common\cibuild.cmd