[EKS] Update to EKS 1.21

[ruecarlo]

• Upgrade all versions and cloudformation entries to EKS 1.21
• update all the tools used by k8s to and eks to latest 1.21
• Update help metrics chart (currently pointing to 2.11.4 stable/metricserver with a WARNING: This chart is Deprecated)
• Code for kube-ops-view does not cover anymore the kube-ops-view. A contribution on a new repository to the open-source version will make sense, and will be appreciated (currently the stable/kube-ops-view throws a warning with chart deprecated)
• Update ec2-instance-selectorto lastest version
• Merge the two spot managed groups into the creation of one file so that the creation takes less time that the two executions that we do at the moment, the eksctl create nodegroup approach is not preferred in this case... We can do a dry run in advance so users see the difference , but we are missing permissions such as cloudwatch, which we recommend later on to use to check what's going on...
• Spot Self Managed Section needs multiple modifications, The labels don't match anymore with the labels that are created for Managed nodegroups which will break the rest of the workshop
• Jenkins section needs update for plugins and update for configuration at the moment it works, but requires quite a lot of changes that are not documented simply in the workshop
• The EMR on EKS needs a brief intro to why we do a few sections... Some sections are introduced without a reference oin why we do them EKS

[ruecarlo]

Updated