Fixes required to use minikube provider

This MR adds a couple of variables that were missing when I tried to use grove's minikube provider.

• Adds S3_STORAGE_BUCKET to the example instance config.yml This variable is required since this merged tutor-contrib-grove!42 (merged)
• Adds TF_VAR_localstack_host and TF_VAR_minikube_host to cluster.yml These variables are required by minikube. Since they are not sensitive, they can live in the cluster.yml file instead of the gitlab CI/CD variables.

Before merge

• Merge grove!285 (closed)
• Update the grove dependency here to latest main.

Local-ref: FAL-3673