Update CODEOWNERS Health Deidentification to use team alias (Azure#43824)

Updated "Health Deidentification" so it uses a team alias instead of user aliases. Left the original user aliases for now.
New team alias reference: https://github.com/orgs/Azure/teams/healthdatadeidentification/members

Author: chrisribe

.github/CODEOWNERS

@@ -455,7 +455,7 @@
 
 # ServiceLabel: %Health Deidentification
 # PRLabel: %Health Deidentification
-/sdk/healthdataaiservices/                           @GrahamMThomas @alexathomases @billwert
+/sdk/healthdataaiservices/                           @GrahamMThomas @alexathomases @billwert @Azure/healthdatadeidentification
 
 # PRLabel: %Event Hubs
 /sdk/eventhubs/microsoft-azure-eventhubs/            @sjkwak