fixup! Deploy a SASL_PLAIN Kafka listener & test notifications against it

Author: delthas

.github/scripts/end2end/configs/notification_destinations.yaml

@@ -38,6 +38,6 @@ spec:
   port: ${NOTIF_KAFKA_AUTH_PORT}
   destinationTopic: ${NOTIF_AUTH_DEST_TOPIC}
   auth: plain
-  basic:
+  plain:
     username: ${NOTIF_AUTH_DEST_USERNAME}
     password: ${NOTIF_AUTH_DEST_PASSWORD}