Revert "CODEOWNERS: add missing not-purely-GCF samples (#1462)"

This reverts commit aa65956.

Author: Ace Nassri

CODEOWNERS

@@ -19,11 +19,6 @@ functions/composer-storage-trigger @leahecole
 functions/scheduleinstance @djmailhot
 functions/speech-to-speech @ricalo
 functions/dialogflow @nnegrey
-functions/memorystore @ericschmidtatwork
-functions/spanner @jsimonweb
-
-# GCF samples outside of functions/
-datastore/functions @benwhitehead
 
 # One-offs
 cloud-sql @kurtisvg