fix policy

[leiicamundi]

Following the upgrade of the EKS module to v20, we encounter a lot of permission denied on the storageclass policy

        	            	�[31m│�[0m �[0m�[1m�[31mError: �[0m�[0m�[1mstorageclasses.storage.k8s.io is forbidden: User "arn:aws:iam::444804106854:user/tf-automation-user" cannot create resource "storageclasses" in API group "storage.k8s.io" at the cluster scope�[0m

e.g. https://github.com/camunda/camunda-tf-eks-module/actions/runs/9957809597

The error is due to a missing dependency between the creation of the cluster and the associated updated of the storage class. This PR solves this issue by moving the storage class definition in the same file.

Also, starting EKS 1.30, gp2 is not the default anymore, I removed it.

This PR also update EKS to v1.30

[leiicamundi]

@Langleu once it's merged, it will unlock #87

Also, I'll tag a new version for this module 2.1.0, then we will be able to merge camunda/camunda-docs#4004