Remove approver-policy versions from install instructions

[inteon]

@wallrj requested these versions to be removed, see https://github.com/cert-manager/website/pull/1439#pullrequestreview-1933998056.

[jetstack-bot]

[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 ask for approval from inteon. For more information see the Kubernetes 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

[netlify[bot]]

✅ Deploy Preview for cert-manager-website ready!

Name	Link
🔨 Latest commit	ef7f20cd8ac2c0cd0bd2d8b29d5406d7c4b74c2f
🔍 Latest deploy log	https://app.netlify.com/sites/cert-manager-website/deploys/6659d5d50d216200088c367b
😎 Deploy Preview	https://deploy-preview-1448--cert-manager-website.netlify.app
📱 Preview on mobile	Toggle QR Code... Use your smartphone camera to open QR code link.

---

To edit notification comments on pull requests, go to your Netlify site configuration.

[cert-manager-prow[bot]]

PR needs rebase.

Instructions for interacting with me using PR comments are available here. If you have questions or suggestions related to my behavior, please file an issue against the kubernetes/test-infra repository.

[cert-manager-prow[bot]]

[APPROVALNOTIFIER] This PR is APPROVED

This pull-request has been approved by: wallrj

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

The pull request process is described here

Needs approval from an approver in each of these files:

• ~~OWNERS~~ [wallrj]

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