chore: clean up last reference to cloud-storage-dpe (#15018)

Missed this in #15000

Author: danielduhh

.github/CODEOWNERS

@@ -6,7 +6,7 @@
 * @googleapis/cloud-cxx-owners
 
 # These libraries are also owned by the GCS clients team.
-/google/cloud/storage/ @googleapis/cloud-storage-dpe @googleapis/cloud-cxx-owners
+/google/cloud/storage/ @googleapis/gcs-sdk-team @googleapis/cloud-cxx-owners
 /google/cloud/storagecontrol/ @googleapis/gcs-sdk-team @googleapis/cloud-cxx-owners
 /google/cloud/storageinsights/ @googleapis/gcs-sdk-team @googleapis/cloud-cxx-owners
 /google/cloud/storagetransfer/ @googleapis/gcs-sdk-team @googleapis/cloud-cxx-owners