Removes the use of `readarray`

Signed-off-by: John T Skarbek <jtslear@gmail.com>

bin/snapshot-dbs

@@ -10,8 +10,11 @@ else
   AZ_RESOURCE_GROUP="PostgresStaging"
 fi
 
+declare -r disk_list='gcloud compute --project $GCP_PROJECT disks list --filter="name~'^postgres-.*-data'" --uri'
+
 declare -a GCP_DISKS
-readarray -t GCP_DISKS < <(gcloud compute --project $GCP_PROJECT disks list --filter="name~'^postgres-.*-data'" --uri)
+GCP_DISKS=($(awk -F= '{print $1}' <(eval $disk_list)))
+
 gcloud compute --project $GCP_PROJECT disks snapshot "${GCP_DISKS[@]}" &
 
 for disk_name in `az disk list -g $AZ_RESOURCE_GROUP -o tsv --query "[*].name"`; do