Move release tools branches from kubebuilder repo

[Adirio]

Description

Move the kubebuilder tools-releases and kube-rbac-proxy-releases branches into this repo.

Steps to reproduce

(I did this from an empty folder)

git clone https://github.com/kubernetes-sigs/kubebuilder.git
git clone https://github.com/kubernetes-sigs/kubebuilder-release-tools.git
cd kubebuilder
git checkout tools-releases
cd ../kubebuilder-release-tools
git switch --orphan control-plane-bundler
cp -r ../kubebuilder/* .
git add .
git commit -m "Bundle k8s 1.20.2 control plane"
git push origin control-plane-bundler
cd ../kubebuilder
git checkout kube-rbac-proxy-releases
cd ../kubebuilder-release-tools
git switch --orphan kube-rbac-proxy
cp -r ../kubebuilder/* .
git add .
git commit -m "Release kube RBAC proxy"
git push origin kube-rbac-proxy

Notes

• I used control-plane-bundler as the branch name as tools-releases inside a repo called kubebuilder-release-tools sounds repetitive. I also changed kube-rbac-proxy-releases to kube-rbac-proxy for the same reason. Feel free to use better suited names if needed.
• I used an orphan branch (no root commit) as the code in the branch is completely independent.
• This process leaves the kubebuilder owners file instead of using the one in this repo, but I don't think that matters. We can update it if needed afterwards.

[Adirio]

@DirectXMan12 This process needs to be done by someone with full write permissions to this repo.

[fejta-bot]

Issues go stale after 90d of inactivity. Mark the issue as fresh with /remove-lifecycle stale. Stale issues rot after an additional 30d of inactivity and eventually close.

If this issue is safe to close now please do so with /close.

Send feedback to sig-contributor-experience at kubernetes/community. /lifecycle stale

[fejta-bot]

Stale issues rot after 30d of inactivity. Mark the issue as fresh with /remove-lifecycle rotten. Rotten issues close after an additional 30d of inactivity.

If this issue is safe to close now please do so with /close.

Send feedback to sig-contributor-experience at kubernetes/community. /lifecycle rotten

[fejta-bot]

Rotten issues close after 30d of inactivity. Reopen the issue with /reopen. Mark the issue as fresh with /remove-lifecycle rotten.

Send feedback to sig-contributor-experience at kubernetes/community. /close

[k8s-ci-robot]

@fejta-bot: Closing this issue.

In response to [this](https://github.com/kubernetes-sigs/kubebuilder-release-tools/issues/31#issuecomment-862334475): >Rotten issues close after 30d of inactivity. >Reopen the issue with `/reopen`. >Mark the issue as fresh with `/remove-lifecycle rotten`. > >Send feedback to sig-contributor-experience at [kubernetes/community](https://github.com/kubernetes/community). >/close 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.

[fejta-bot]

Rotten issues close after 30d of inactivity. Reopen the issue with /reopen. Mark the issue as fresh with /remove-lifecycle rotten.

Send feedback to sig-contributor-experience at kubernetes/community. /close

[k8s-ci-robot]

@fejta-bot: Closing this issue.

In response to [this](https://github.com/kubernetes-sigs/kubebuilder-release-tools/issues/31#issuecomment-883320591): >Rotten issues close after 30d of inactivity. >Reopen the issue with `/reopen`. >Mark the issue as fresh with `/remove-lifecycle rotten`. > >Send feedback to sig-contributor-experience at [kubernetes/community](https://github.com/kubernetes/community). >/close 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.