⚠️ Remove clusterctl restore command and Restore function from Client interface

[hackeramitkumar]

What this PR does / why we need it:

• Removes the clusterctl restore command
• Removes the Restore function in Client interface
• Removes tests
• Updates docs

Which issue(s) this PR fixes (optional, in fixes #<issue number>(, fixes #<issue_number>, ...) format, will close the issue(s) when PR gets merged):
Part of #7713

cc @kubernetes-sigs/cluster-api-release-team

[ykakarap]

Thank you @hackeramitkumar for working on this.

Overall LGTM. Just one comment.

[k8s-ci-robot]

@hackeramitkumar: The following test failed, say /retest to rerun all failed tests or /retest-required to rerun all mandatory failed tests:

Test name	Commit	Details	Required	Rerun command
pull-cluster-api-apidiff-main	c1d8504	link	false	/test pull-cluster-api-apidiff-main

Full PR test history. Your PR dashboard. Please help us cut down on flakes by linking to an open issue when you hit one in your PR.

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. I understand the commands that are listed here.

[ykakarap]

Thank you 🙂

/lgtm

[k8s-ci-robot]

LGTM label has been added.

Git tree hash: 9037f8962d354190710cec7822e140fe35340a78

[sbueringer]

Perfet. Thank you very much!!

/lgtm
/approve

[k8s-ci-robot]

[APPROVALNOTIFIER] This PR is APPROVED

This pull-request has been approved by: sbueringer

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 [sbueringer]

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