Switch vsix packing to use Nuget.config (#14209)

* Add a NuGet.config file

Author: sean-mcmanus

Build/package/jobs_package_vsix.yml

@@ -54,8 +54,21 @@ jobs:
       vsce package -o $(Build.ArtifactStagingDirectory)\vsix\${{ parameters.vsixName }}
     displayName: Run VSCE to package vsix
 
-  - task: Npm@0
-    displayName: Uninstall vsce
+# sign the vsix
+  - script: vsce generate-manifest -i $(Build.ArtifactStagingDirectory)\vsix\${{ parameters.vsixName }}.vsix -o $(Build.ArtifactStagingDirectory)\vsix\${{ parameters.vsixName }}.manifest
+    displayName: generate manifest
+    workingDirectory: $(Build.SourcesDirectory)\${{ parameters.srcDir }}
+  - script: copy $(Build.ArtifactStagingDirectory)\vsix\${{ parameters.vsixName }}.manifest $(Build.ArtifactStagingDirectory)\vsix\${{ parameters.vsixName }}.signature.p7s
+    displayName: prepare manifest for signing
+    workingDirectory: $(Build.SourcesDirectory)\${{ parameters.srcDir }}
+  - task: NuGetToolInstaller@1
+    displayName: Install NuGet
+  - task: NuGetAuthenticate@1
+    displayName: Authenticate NuGet
+  - script: nuget restore $(Build.SourcesDirectory)\Build\signing\SignVsix.proj -PackagesDirectory $(Build.SourcesDirectory)\Build\signing\packages -ConfigFile $(Build.SourcesDirectory)\Build\signing\NuGet.config
+    displayName: Restore MicroBuild Core
+  - task: MSBuild@1
+    displayName: Sign the vsix
     inputs:
       command: uninstall
       arguments: --global @vscode/vsce

Build/signing/NuGet.config

@@ -0,0 +1,7 @@
+<?xml version="1.0" encoding="utf-8"?>
+<configuration>
+  <packageSources>
+    <clear />
+    <add key="Engineering" value="https://pkgs.dev.azure.com/devdiv/_packaging/MicroBuildToolset/nuget/v3/index.json" />
+  </packageSources>
+</configuration>