kubernetes: replace the existing PR and release blocking kube-up based jobs with CAPI jobs

had a discussion with @timothysc about this yesterday.

this is a tracking issue for replacing the pending PR and release blocking jobs based on kube-up with Cluster API (CAPI) provider alternatives over time.

ideally:

• the replacement jobs should co-existing in parallel with the kube-up jobs.
• once the replacement jobs are stable the kube-up jobs should be removed.

xref issue for removing the /cluster directory: https://github.com/kubernetes/kubernetes/issues/78995 which can be considered a parent of this one.

TODO:

• enumerate the current list of PR and release blocking jobs assigned: @neolit123

see: https://github.com/kubernetes/kubernetes/issues/82532#issuecomment-536783242 https://github.com/kubernetes/kubernetes/issues/82532#issuecomment-536802097

• experiment replacing pull-kubernetes-e2e-gce with a CAPA (cluster-api AWS) / CAPG (cluster-api GCP) job assigned: @mariantalla ATM CAPA is the most complete provider. there was a discussion here and during the sig-arch code organization meeting about this being the first step we can take. ideally we should be using CAPG (GCP provider).

• estimate if/how can we replace the big SIG scalability jobs using Cluster API, assigned: @timothysc @timothysc mentioned that currently there are TODOs there to enable support for large number of nodes in CAPI.

• replace SIG-Windows kube-up jobs assigned: TODO this is one of the trickier items actually, since CAPI does not support Windows.

/sig testing cloud-provider cluster-lifecycle release scalability /kind feature /area test /priority important-longterm /assign @spiffxp @justinsb @timothysc /assign