Test longhorn deployment in baremetal CI

MR !272 (diffs) brings the ability to deploy longhorn in workload cluster But because our current CI only relies on CAPO, and as longhorn does not make sense in such case, Longhorn deployment is not tested yet.

We'll need to include Longhorn deployment and testing in Sylva baremetal CI. And besides the deployment phase, we should also include some tests to confirm that it's functional