Remove (some) excessive inline comment links

These often go out of date, and add more clutter than help. I would
like us to only add links like these when they are unobvious.

terraform/aws/efs.tf

@@ -4,7 +4,6 @@
 // the nodes. We create a mount target for each EFS, in each subnet, even if we
 // primarily put all our nodes in one - this allows for GPU nodes to be spread
 // out across AZ when needed
-# ref: https://registry.terraform.io/providers/hashicorp/aws/latest/docs/data-sources/subnets
 data "aws_subnets" "cluster_node_subnets" {
 
   filter {
@@ -23,7 +22,6 @@ data "aws_subnets" "cluster_node_subnets" {
   }
 }
 
-# ref: https://registry.terraform.io/providers/hashicorp/aws/latest/docs/data-sources/security_group
 data "aws_security_group" "cluster_nodes_shared_security_group" {
 
   filter {
@@ -44,7 +42,6 @@ data "aws_security_group" "cluster_nodes_shared_security_group" {
 # This allows supporting running multiple EFS instances in a cluster
 # for an accurate cost allocation per hub of home directory storage.
 # https://github.com/2i2c-org/infrastructure/issues/4453
-# ref: https://registry.terraform.io/providers/hashicorp/aws/latest/docs/resources/efs_file_system
 resource "aws_efs_file_system" "hub_homedirs" {
   for_each = var.filestores
   tags = merge(each.value.tags, {
@@ -102,7 +99,6 @@ locals {
   ]
 }
 
-# ref: https://registry.terraform.io/providers/-/aws/latest/docs/resources/efs_mount_target
 resource "aws_efs_mount_target" "hub_homedirs" {
   for_each = tomap({
     for mount_target in local.efs_mount_targets : "${mount_target.subnet_id}.${mount_target.name}" => mount_target
@@ -119,7 +115,6 @@ output "nfs_server_dns_map" {
 
 # Enable automatic backups for user homedirectories
 # Documented in https://docs.aws.amazon.com/efs/latest/ug/awsbackup.html#automatic-backups
-# ref: https://registry.terraform.io/providers/hashicorp/aws/latest/docs/resources/efs_backup_policy
 resource "aws_efs_backup_policy" "hub_homedirs" {
   for_each       = aws_efs_file_system.hub_homedirs
   file_system_id = each.value.id