Merge local minikube and integration tests env setups

[alexgeorgousis]

We currently have 2 minikube setups:

• One spun up by the integration-test-up make target used for workflow factory integration tests
• One spun up by the minikube-up make target used to provide a local manual testing environment

I think the 2 should be merged because:

1. Makefile cohesion - it's strange to have 2 separate things that do something quite similar
2. Provider tests: We should use 1 integration-test-up make target for all integration tests, but we need some things from minikube-up (e.g. installing the operator) for provider tests to work - so we might as well merge them instead of duuplicating