Automatic merge from submit-queue (batch tested with PRs 56894, 56940, 55223, 56554, 54985). If you want to cherry-pick this change to another branch, please follow the instructions <a href="https://github.com/kubernetes/community/blob/master/contributors/devel/cherry-picks.md">here</a>.

Remove dead code in winkernel proxy UT

**What this PR does / why we need it**:

There is a `+build windows` tag in `pkg/proxy/winkernel/proxier_test.go`, it means the UTs will not run in upstream CI. Plus, the UT codes in  `pkg/proxy/winkernel/proxier_test.go` are not for winkernel proxier, instead they are for iptables proxier!

We should remove the dead code in winkernel proxy UT and then create the winkernel-specific UTs.

**Which issue(s) this PR fixes**:
Fixes #56555

**Special notes for your reviewer**:

**Release note**:

```release-note
NONE
```