Sync eng/common directory with azure-sdk-tools repository (#16269)

eng/common/pipelines/templates/steps/bypass-local-dns.yml

@@ -3,4 +3,9 @@ steps:
     # https://github.com/actions/virtual-environments/issues/798
     - script: sudo ln -sf /run/systemd/resolve/resolv.conf /etc/resolv.conf
       displayName: Bypass local DNS server to workaround issue resolving cognitiveservices names
-      condition: and(succeededOrFailed(), eq(variables['OSVmImage'], 'ubuntu-18.04'))
+      condition: |
+        and(
+          succeededOrFailed(),
+          eq(variables['OSVmImage'], 'ubuntu-18.04'),
+          eq(variables['Container'], '')
+        )

eng/common/pipelines/templates/steps/verify-agent-os.yml

@@ -1,4 +1,4 @@
-parameters: 
+parameters:
   OSVmImage: $(OSVmImage)
 
 steps:

eng/common/scripts/Delete-RemoteTag.ps1

@@ -0,0 +1,33 @@
+param(
+  $Repository,
+  $Tag,
+  $AuthToken
+)
+
+. (Join-Path $PSScriptRoot common.ps1)
+
+$repositoryParts = $Repository.Split("/")
+
+if ($repositoryParts.Length -ne 2)
+{
+    LogError "Repository is not a valid format."
+}
+
+$repositoryOwner = $repositoryParts[0]
+LogDebug "Repository owner is: $repositoryOwner"
+
+$repositoryName = $repositoryParts[1]
+LogDebug "Reposiory name is: $repositoryName"
+
+$ref = "tags/$Tag"
+LogDebug "Calculated ref is: $ref"
+
+try
+{
+    Remove-GitHubSourceReferences -RepoOwner $repositoryOwner -RepoName $repositoryName -Ref $ref -AuthToken $AuthToken
+}
+catch
+{
+  LogError "Remove-GitHubSourceReferences failed with exception:`n$_"
+  exit 1
+}