Uninstall-DbaSqlWatch - Skip DACPAC unregister when no registration exists

Fixes test failures where Install-DbaSqlWatch's post-deployment script
times out, leaving schema objects deployed but no DAC registration in
msdb. The unconditional Unregister() call then threw 'DacInstance with
the specified instance_id does not exist'.

Now checks GetDatabases() before calling Unregister() so cleanup is
safe regardless of whether the DACPAC registration completed.

(do *SqlWatch*)

Co-authored-by: Andreas Jordan <andreasjordan@users.noreply.github.com>

Author: github-actions[bot]

public/Uninstall-DbaSqlWatch.ps1

@@ -212,7 +212,12 @@ Function Uninstall-DbaSqlWatch {
                     Write-Message -Level Verbose -Message "Unpublishing SqlWatch DACPAC from $database on $server."
                     $connectionString = $server.ConnectionContext.ConnectionString | Convert-ConnectionString
                     $dacServices = New-Object Microsoft.SqlServer.Dac.DacServices $connectionString
-                    $dacServices.Unregister($Database)
+                    $registeredDatabases = $dacServices.GetDatabases()
+                    if ($Database -in $registeredDatabases) {
+                        $dacServices.Unregister($Database)
+                    } else {
+                        Write-Message -Level Verbose -Message "No DACPAC registration found for $database on $server, skipping unregister."
+                    }
                 } catch {
                     Stop-Function -Message "Failed to unpublish SqlWatch DACPAC from $database on $server." -ErrorRecord $_
                 }