Replace remaining jetstack-bot references with cert-manager-bot

[cert-manager-bot]

Should fix this failure: https://prow.infra.cert-manager.io/view/gs/cert-manager-prow-artifacts/logs/periodic-testing-autobump/1780267308703289344

[cert-manager-bot]

/approve /lgtm self-lgtm'ng since this is a straight-forward bugfix.

[cert-manager-prow[bot]]

@cert-manager-bot: you cannot LGTM your own PR.

In response to [this](https://github.com/cert-manager/testing/pull/980#issuecomment-2059538620): >/approve >/lgtm >self-lgtm'ng since this is a straight-forward bugfix. Instructions for interacting with me using PR comments are available [here](https://git.k8s.io/community/contributors/guide/pull-requests.md). If you have questions or suggestions related to my behavior, please file an issue against the [kubernetes/test-infra](https://github.com/kubernetes/test-infra/issues/new?title=Prow%20issue:) repository.

[inteon]

Sorry for the confusion, I was still using the cert-manager-bot account, but I was the one who created this PR.

[cert-manager-prow[bot]]

[APPROVALNOTIFIER] This PR is APPROVED

Approval requirements bypassed by manually added approval.

This pull-request has been approved by: cert-manager-bot

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](https://github.com/cert-manager/testing/blob/master/OWNERS)** Approvers can indicate their approval by writing `/approve` in a comment Approvers can cancel approval by writing `/approve cancel` in a comment