[eks] [nodegroup stucked]: Cannot delete nodegroup due to auth configmap damaged.

I have created an EKS cluster and nodegroup using a cloudformation template that I have created, but in the creation process there was an error:
Nodegroup ng-eks-A failed to stabilize: [{Code: AccessDenied,Message: The aws-auth ConfigMap in your cluster is invalid }]

After that, I tried to delete the nodegroup but it was unsuccessful, I have applied a configmap to authorize my user and it applied correctly (apparently) but still I am not able to delete it. What can I do to delete the nodegroup and the cluster?

Start with the reported CloudFormation EKS nodegroup creation error and inspect the cluster's aws-auth ConfigMap and nodegroup deletion state. Determine the supported recovery path for the stuck nodegroup and cluster, then document the verified steps and expected outcome.

Written by the indexing model from the issue text.