chore(deps): update cilium images (minor)

[gardener-ci-robot]

This PR contains the following updates:

Package	Update	Change
quay.io/cilium/certgen	minor	v0.2.4 -> v0.3.1
quay.io/cilium/cilium	minor	v1.17.9 -> v1.18.4
quay.io/cilium/hubble-relay	minor	v1.17.9 -> v1.18.4
quay.io/cilium/operator	minor	v1.17.9 -> v1.18.4

---

Configuration

📅 Schedule: Branch creation - At any time (no schedule defined), Automerge - At any time (no schedule defined).

🚦 Automerge: Disabled by config. Please merge this manually once you are satisfied.

♻ Rebasing: Whenever PR becomes conflicted, or you tick the rebase/retry checkbox.

👻 Immortal: This PR will be recreated if closed unmerged. Get config help if that's undesired.

---

• If you want to rebase/retry this PR, check this box

---

This PR has been generated by Renovate Bot.

[gardener-prow]

[APPROVALNOTIFIER] This PR is NOT APPROVED

This pull-request has been approved by:
Once this PR has been reviewed and has the lgtm label, please assign docktofuture for approval. For more information see the Code Review Process.

The full list of commands accepted by this bot can be found here.

Needs approval from an approver in each of these files:

• OWNERS

Approvers can indicate their approval by writing /approve in a comment
Approvers can cancel approval by writing /approve cancel in a comment