Switch to PowerShell Gallery mirror (#5150)

Author: andyleejordan

.pipelines/vscode-powershell-Official.yml

@@ -172,10 +172,7 @@ extends:
               $manifest = Test-ModuleManifest $(Build.SourcesDirectory)/modules/PowerShellEditorServices/PowerShellEditorServices.psd1
               Write-Host Using PowerShellEditorServices v$($manifest.Version)
             displayName: PowerShellEditorServices version
-          - pwsh: |
-              Register-PSRepository -Name CFS -SourceLocation "https://pkgs.dev.azure.com/powershell/PowerShell/_packaging/powershell/nuget/v2" -InstallationPolicy Trusted
-              Install-Module -Repository CFS -Name Microsoft.PowerShell.PSResourceGet
-              ./tools/installPSResources.ps1 -PSRepository CFS
+          - pwsh: ./tools/installPSResources.ps1 -PSRepository CFS
             displayName: Install PSResources
           - pwsh: Invoke-Build Test -Configuration $(BuildConfiguration)
             displayName: Run tests

tools/installPSResources.ps1

@@ -6,7 +6,7 @@ param(
 )
 
 if ($PSRepository -eq "CFS" -and -not (Get-PSResourceRepository -Name CFS -ErrorAction SilentlyContinue)) {
-    Register-PSResourceRepository -Name CFS -Uri "https://pkgs.dev.azure.com/powershell/PowerShell/_packaging/powershell/nuget/v3/index.json"
+    Register-PSResourceRepository -Name CFS -Uri "https://pkgs.dev.azure.com/powershell/PowerShell/_packaging/PowerShellGalleryMirror/nuget/v3/index.json"
 }
 
 # NOTE: Due to a bug in Install-PSResource with upstream feeds, we have to