feat(kubeovn-operator): update Kube-OVN upstream to v1.15.4 (backport #236)

[mergify]

Problem:

Solution:

Related Issue(s):

harvester/harvester#10089

Test plan:

Additional documentation or context

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This is an automatic backport of pull request #236 done by [Mergify](https://mergify.com).

[mergify]

Cherry-pick of 8bb6de7 has failed:

On branch mergify/bp/v1.8/pr-236
Your branch is up to date with 'origin/v1.8'.

You are currently cherry-picking commit 8bb6de7.
  (fix conflicts and run "git cherry-pick --continue")
  (use "git cherry-pick --skip" to skip this patch)
  (use "git cherry-pick --abort" to cancel the cherry-pick operation)

Unmerged paths:
  (use "git add <file>..." to mark resolution)
	both modified:   version_info

no changes added to commit (use "git add" and/or "git commit -a")

To fix up this pull request, you can check it out locally. See documentation: https://docs.github.com/en/pull-requests/collaborating-with-pull-requests/reviewing-changes-in-pull-requests/checking-out-pull-requests-locally

[starbops]

The conflict has been fixed.