Is your proposed feature related to a problem?

None of the E2E tests currently use Cilium with a delegated IPAM plugin.

Describe the feature you'd like

Add an E2E test that runs Cilium in delegated IPAM mode, preferrably validating both IPv4 and IPv6.

(Optional) Describe your proposed solution

It should be possible to validate this in a kind cluster using one of the reference CNI IPAM plugins.

The default CNI (kindnet) does not support overriding the conflist (see Antonio's response here aojea/kindnet#22) , so we would need to disable the default CNI in kind and install everything ourselves.