Get correct digests (#561)

Get the correct digest for marking stale

Co-authored-by: freddydk <freddydk@users.noreply.github.com>

.github/workflows/BuildMissingImages.yaml

@@ -43,11 +43,8 @@ jobs:
             }
             $digests = $tags | ForEach-Object {
                 Write-Host -NoNewline "$_ : "
-                $webclient = New-Object System.Net.WebClient
-                $webclient.Headers.Add('Accept', 'application/vnd.docker.distribution.manifest.v2+json')
-                $manifest = $webclient.DownloadString("https://mcr.microsoft.com/v2/businesscentral/manifests/$_") | ConvertFrom-Json
-                Write-Host $manifest.config.digest
-                $manifest.config.digest
+                $manifest = docker manifest inspect mcr.microsoft.com/businesscentral:$_ -v | ConvertFrom-Json
+                $manifest.Descriptor.digest
             } | Select-Object -Unique
             Set-Location "generic"
             $rootPath = Get-Location