Adopt ocpctl in the service provider debugging guide

[maximiliantech]

What would you like to be added?

The service provider debugging guide at https://open-control-plane.io/developers/serviceprovider/debugging should reference ocpctl instead of the local-dev.sh script from cluster-provider-kind.

The mapping is:

Today (script)	Target (ocpctl)
./hack/local-dev.sh deploy	ocpctl env apply <name>
./hack/local-dev.sh reset --force	ocpctl env delete <name> followed by ocpctl env apply <name>
environment variable overrides for images and versions	ocpctl env apply --config <file> with the Environment config (operator.image, clusterProviders[].image, serviceProviders[].image)

The migration also depends on openmcp-project/ocpctl#40 to cover the access-platform-cluster workflow.

Why is this needed?

ocpctl is positioned as the supported CLI for local OpenControlPlane environments, while the debugging guide still drives developers through a script in a different repository. Consolidating on ocpctl gives service provider developers a single, supported entry point and lets us retire the duplicate workflow in cluster-provider-kind/hack/local-dev.sh.