CH-145 Add spec.ingressClassName to ingress template

[condar-metacell]

Closes CH-145

Added spec.ingressClassName to the ingress template, left the kubernetes.io/ingress.class annotation as it is still required by Google Kubernetes Engine that we deploy to.

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Deploy to a local Kubernetes cluster, there should be no functional change but the warning about deprecated annotation should no longer be present.

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Nice to have (if relevant):

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[filippomc]

LGTM