[FEATURE] Migrate to the official Upbound AWS provider (EKS cluster)

This issue is for migrating from community AWS provider to the official Upbound AWS provider. The scope of this issue is the EKS cluster composition.

**Changes:**
1. Install the official Upbound AWS provider -- this requires changes at `repos/gitops-system/tools/crossplane/` i.e. adding the providers installation manifests. Note that the Upbound provider is broken down into service-level providers, and given that EKS cluster creation involves creating several cloud resources, several providers will be required -- this include: provider-aws-eks, provider-aws-vpc, provider-aws-ec2, and provider-aws-iam. A `Kustomization` has to be added under flux folder of the management cluster `repos/gitops-system/cluster/mgmt/` for reconciling the installation manifests.
2. Updating EKS composition to use the MRs of the new providers -- this requires changes at `repos/gitops-system/tools-config/crossplane-eks-composition/`; the interface (XRD) should be kept the same.

Inizia esaminando i manifest esistenti in repos/gitops-system/tools/crossplane/ e i file Flux del cluster di gestione in repos/gitops-system/cluster/mgmt/. Poi analizza la composizione EKS in repos/gitops-system/tools-config/crossplane-eks-composition/ e confronta le relative risorse gestite con i provider ufficiali a livello di servizio. Il lavoro è completato quando i provider eseguono il reconcile, la composizione EKS li utilizza e l’interfaccia XRD rimane invariata.

Scritto dal modello di indicizzazione a partire dal testo della issue.