🌱 : (fix golint) - Remove deprecated io/ioutil and use os, io instead

[manu12miskin]

Summary:

This PR fixes the following error by removing deprecated io/ioutil and using os, io instead.

pkg/cli/alpha/config-gen/cmd.go:22:2: SA1019: "io/ioutil" has been deprecated since Go 1.16: As of Go 1.16, the same functionality is now provided by package io or package os, and those implementations should be preferred in new code. See the specific function documentation for details. (staticcheck)
	"io/ioutil"

Description of change:

• Update ioutil.ReadAll => io.ReadAll
• Update ioutil.ReadFile => os.ReadFile
• Update ioutil.WriteFile => os.WriteFile

Motivation:

Helps resolve #2928

[k8s-ci-robot]

Hi @manu12miskin. Thanks for your PR.

I'm waiting for a kubernetes-sigs member to verify that this patch is reasonable to test. If it is, they should reply with /ok-to-test on its own line. Until that is done, I will not automatically test new commits in this PR, but the usual testing commands by org members will still work. Regular contributors should join the org to skip this step.

Once the patch is verified, the new status will be reflected by the ok-to-test label.

I understand the commands that are listed here.

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.

[camilamacedo86]

/ok-to-test
/approved

[camilamacedo86]

Hi @manu12miskin,

Thank you for your contribution. 🥇

See that this change does not affect end-users.
The goal is to fix the golint replacing the deprecated code.

Therefore, we use the emojis and the titles to generate the changelog.
So, I hope that you do not mind but I update the title accordingly.
For a better understanding see the contribution guide.: https://github.com/kubernetes-sigs/kubebuilder/blob/master/CONTRIBUTING.md#pr-process

[camilamacedo86]

/lgtm
/approved

[camilamacedo86]

/approved

[k8s-ci-robot]

[APPROVALNOTIFIER] This PR is APPROVED

This pull-request has been approved by: camilamacedo86, manu12miskin

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 [camilamacedo86]

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