Drive it for a long time or until state inspection time.
The SAI system injects air into the exhaust upstream of the cats to get them to "light" sooner. It is a pollution control help.
If your pump has stopped working you might be able to take it apart and clean the carbon out of the disks that make up the air pump end of it. If the motor has failed you can buy a new Porsche branded Bosch SAI pump from Porsche for ~$1000 or get the same Bosch pump from a supplier for ~$300.
03 2003 Porsche 911 Air Pump - Air Intake - Bosch, Genuine - *********