[Search] Remove myself from CODEOWNERS (#23560)

I no longer work on the Azure AI Search team, so I'm removing myself from CODEOWNERS to stop having issues @-mention me.

.github/CODEOWNERS

@@ -486,7 +486,7 @@
 #/<NotInRepo>/          @derek1ee
 
 # ServiceLabel: %Search
-#/<NotInRepo>/          @brjohnstmsft @bleroy @tjacobhi @markheff @miwelsh
+#/<NotInRepo>/          @bleroy @tjacobhi @markheff @miwelsh
 
 # ServiceLabel: %Security
 #/<NotInRepo>/          @chlahav