aws docs: remove redundant eksctl create identitymapping step for o…

…ther engineers

This is no longer needed as a parallel system for granting AWS users
access to EKS clusters have been created called EKS Access entries, and
it grants AWS account admin users access by default, and not just the
creator of the EKS cluster, so this step is no longer needed.

docs/hub-deployment-guide/new-cluster/new-cluster.md

@@ -674,46 +674,19 @@ First, we need to grant the freshly created deployer IAM user access to the kube
 
   It should show you the provisioned node on the cluster if everything works out ok.
 
-### Grant `eksctl` access to other users
+### (no longer needed) Grant `eksctl` access to other users
 
-```{note}
-This section is still required even if the account is managed by SSO. Though a
-user could run `deployer use-cluster-credentials $CLUSTER_NAME` to gain access
-as well.
-```
-
-AWS EKS has a strange access control problem, where the IAM user who creates
-the cluster has [full access without any visible settings
-changes](https://docs.aws.amazon.com/eks/latest/userguide/add-user-role.html),
-and nobody else does. You need to explicitly grant access to other users. Find
-the usernames of the 2i2c engineers on this particular AWS account, and run the
-following command to give them access:
+Use of `eksctl create iamidentitymapping` was previously required step to grant
+access to other engineers, but after AWS introduced a new system in parallel to
+the now deprecated `iamidentitymapping` system, it seems AWS account admin users
+are no longer required to be granted access like this.
 
-```{note}
-You can modify the command output by running `terraform output -raw eksctl_iam_command` as described in [](new-cluster:terraform:cluster-credentials).
-```
-
-```bash
-eksctl create iamidentitymapping \
-   --cluster $CLUSTER_NAME \
-   --region $CLUSTER_REGION \
-   --arn arn:aws:iam::<aws-account-id>:user/<iam-user-name> \
-   --username <iam-user-name> \
-   --group system:masters
-```
-
-This gives all the users full access to the entire kubernetes cluster.
-After this step is done, they can fetch local config with:
+To conclude, any AWS account admin authenticated should be able to acquire k8s
+cluster credentials like below without use of `eksctl create iamidentitymapping`:
 
 ```bash
 aws eks update-kubeconfig --name=$CLUSTER_NAME --region=$CLUSTER_REGION
 ```
-
-This should eventually be converted to use an [IAM Role] instead, so we need not
-give each individual user access, but just grant access to the role - and users
-can modify them as they wish.
-
-[iam role]: https://docs.aws.amazon.com/IAM/latest/UserGuide/id_roles.html
 ````
 
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