node: Skip ipcache for remote node IPs if IPsec is enabled
node: Skip ipcache for remote node IPs if IPsec is enabled

Before this commit, if IPsec is enabled, we add all remote node IP
addresses to the ipcache of all nodes, regardless of whether
enable-remote-node-identity is true or false.

This commit reverts that behavior to only add those IP addresses if
remote-node identities, node encryption, or encryption+tunneling are
enabled. If encryption+native routing is enabled, we don't need to
expose the remote node IP addresses via the ipcache.

Signed-off-by: Paul Chaignon <a027184a55211cd23e3f3094f1fdc728df5e0500@cilium.io>

cilium/cilium,tklauser/cilium,cilium/cilium,michi-covalent/cilium,michi-covalent/cilium,tklauser/cilium,cilium/cilium,tklauser/cilium,cilium/cilium,cilium/cilium,michi-covalent/cilium,michi-covalent/cilium,tklauser/cilium,michi-covalent/cilium,tklauser/cilium