[ko] Remove unmaintained Weave Net and Romana network policy provider pages

**This is a Feature Request**

**What would you like to be added**

The English pages for the Weave Net and Romana network policy providers were removed in #56746 because both projects are unmaintained — Weave Net was archived in 2024 and Romana has not been updated since 2019. See #56735 for the original discussion.

That change touched only the English content and `static/_redirects.base`, so the Korean localization still ships both pages:

- `content/ko/docs/tasks/administer-cluster/network-policy-provider/romana-network-policy.md`
- `content/ko/docs/tasks/administer-cluster/network-policy-provider/weave-network-policy.md`

`content/ko/docs/tasks/administer-cluster/declare-network-policy.md` also still lists both providers, so Korean readers are pointed to them from the task page.

I would like to mirror the English change in the Korean localization by removing both pages and dropping the two links from `declare-network-policy.md`.

**Website Link**

- Korean: https://kubernetes.io/ko/docs/tasks/administer-cluster/declare-network-policy/
- English: https://kubernetes.io/docs/tasks/administer-cluster/declare-network-policy/

**Why is this needed**

Korean readers are still directed to two unmaintained network policy providers. Weave Net in particular no longer receives any fixes, including security fixes.

**Comments**

The redirects added in #56746 cover the English URLs only. I will ask in the pull request whether equivalent `/ko/` entries should be added to `static/_redirects.base`.

/area localization
/language ko
/assign