chore: update sigs.k8s.io/karpenter to v1.4.0

[tallaxes]

Description

Update sigs.k8s.io/karpenter to v1.4.0. Most of the changes in provider are straightforward, here are some less obvious:

• Remove support for webhooks
• Remove alternative operator - should no longer be needed
• Minimal support for Node Repair policies introduced, disabled (behind feature flag), enabled for testing only 9d265f1
• Have instance Delete call Get first (including to satisfy new sigs.k8s.io/karpenter expectation) e283696
• Restore "should drain pods on a node in order" E2E test (now supported) f848350
• "karpenter.azure.com/aksnodeclass" label (used internally) is allowed

How was this change tested?

• make presubmit
• E2E:
  • https://github.com/Azure/karpenter-provider-azure/actions/runs/14214116697 (9d265f1) ✅
  • https://github.com/Azure/karpenter-provider-azure/actions/runs/14248373209 (f848350) ✅
  • https://github.com/Azure/karpenter-provider-azure/actions/runs/14526432427 (b796333) ✅ - latest

Does this change impact docs?

• Yes, PR includes docs updates
• Yes, issue opened: #
• No

Release Note

[coveralls]

Pull Request Test Coverage Report for Build 12698619779

Warning: This coverage report may be inaccurate.

This pull request's base commit is no longer the HEAD commit of its target branch. This means it includes changes from outside the original pull request, including, potentially, unrelated coverage changes.

• For more information on this, see Tracking coverage changes with pull request builds.
• To avoid this issue with future PRs, see these Recommended CI Configurations.
• For a quick fix, rebase this PR at GitHub. Your next report should be accurate.

Details

• 2 of 12 (16.67%) changed or added relevant lines in 1 file are covered.
• No unchanged relevant lines lost coverage.
• Overall coverage increased (+0.03%) to 95.453%

---

Changes Missing Coverage	Covered Lines	Changed/Added Lines	%
pkg/cloudprovider/cloudprovider.go	2	12	16.67%

Totals
Change from base Build 12678197330:	0.03%
Covered Lines:	47742
Relevant Lines:	50016

---

💛 - Coveralls

[charliedmcb]

First quick pass completed. Few minor comments. Will take a closer look at a few sections tomorrow.

[charliedmcb]

Only gave it a quicker review, but nothing jumped out and looks good to me.

Do think it's best to get a little longer pass review from someone before completing though for assurance.