fix: @mention owner for module issues, if GH handle can't be found du…

…e to GH bug (#1118)

When a module issue is raised, the workflow should automatically assign
the owner to it. Unfortunately due to a bug in GH, see
cli/cli#6235, the GH handle is sometimes not
found. As a workaround, the owner will then in this case be @mentioned
in a comment.

avm/utilities/pipelines/platform/Set-AvmGitHubIssueOwnerConfig.ps1

@@ -131,8 +131,8 @@ A member of the @azure/$($module.ModuleOwnersGHTeam) or @azure/$($module.ModuleC
     }
 
     if ([String]::IsNullOrEmpty($assign)) {
-      $reply = "This issue couldn't be assigend to $($module.PrimaryModuleOwnerGHHandle), because no such users exists."
       if ($PSCmdlet.ShouldProcess("missing user comment to issue [$($issue.title)]", 'Add')) {
+        $reply = "This issue couldn't be assigend due to an internal error. @$($module.PrimaryModuleOwnerGHHandle), please make sure this issue is assigned to you and please provide an initial response within 5 business days."
         gh issue comment $issue.url --body $reply --repo $Repo
       }
     }