[CODEOWNERS] Fix linter failures (Azure#47486)

The focus of these changes is to remove a set of owners who are no longer valid.

Author: jsquire

.github/CODEOWNERS

@@ -1039,12 +1039,6 @@
 # ServiceLabel: %Operator Nexus - Network Cloud %Mgmt
 # ServiceOwners:                                                   @Azure/azure-sdk-write-networkcloud
 
-# PRLabel: %Oracle
-/sdk/oracle/Azure.ResourceManager.*/                               @v-jamcheung @v-rvilathurs @v-eelhomsi
-
-# ServiceLabel: %Oracle %Mgmt
-# ServiceOwners:                                                   @v-jamcheung @v-rvilathurs @v-eelhomsi
-
 # PRLabel: %Quota
 /sdk/quota/Azure.ResourceManager.*/                                @tejasm-microsoft