Use nftablesMode=Auto in FelixConfiguration

[caseydavenport]

Description

Built on top of projectcalico/calico#11629

felix can now auto-detect whether the local kube-proxy is using iptables or nftables, and act accordingly.

This tells the operator to defer that decision to Felix - allowing for easier rolling upgrades to nftables mode.

We don't do this for BPF, instead keeping an explicit "Enabled", since kube-proxy isn't used in BPF mode.

Release Note

Auto-detect kube-proxy nftables/iptables mode.

For PR author

• Tests for change.
• If changing pkg/apis/, run make gen-files
• If changing versions, run make gen-versions

For PR reviewers

A note for code reviewers - all pull requests must have the following:

• Milestone set according to targeted release.
• Appropriate labels:
  • kind/bug if this is a bugfix.
  • kind/enhancement if this is a a new feature.
  • enterprise if this PR applies to Calico Enterprise only.