add code owner to synapse (#16230)

Author: wanyang7

CODEOWNERS

@@ -76,7 +76,7 @@
 /specification/storsimple8000series/ @manaas-microsoft
 /specification/streamanalytics/ @atpham256
 /specification/subscriptions/ @navysingla
-/specification/synapse/ @idear1203
+/specification/synapse/ @idear1203 @wonner
 /specification/timeseriesinsights/ @sandshadow
 /specification/trafficmanager/ @allencal @hrkulkarmsft
 /specification/web/ @naveedaz @Azure/azure-app-service-control-plane