[CODEOWNERS] Remove invalid account (Azure#48369)

The focus of these changes is to address a linter failure flagging an owner account as invalid.

Author: jsquire

.github/CODEOWNERS

@@ -330,7 +330,7 @@
 /sdk/communication/Azure.Communication.Identity/                   @Azure/acs-identity-sdk @AikoBB @maximrytych-ms @mjafferi-msft
 
 # PRLabel: %Communication - Phone Numbers
-/sdk/communication/Azure.Communication.PhoneNumbers/               @miguhern @whisper6284 @danielav7
+/sdk/communication/Azure.Communication.PhoneNumbers/               @whisper6284 @danielav7
 
 # PRLabel: %Communication - Programmable Connectivity
 /sdk/communication/Azure.Communication.ProgrammableConnectivity/   @Azure/azure-sdk-write-communication