migrate Deployment from extensions/v1beta1 to apps/v1

[oke-py]

Fixes #3552

Description

migrate Deployment from extensions/v1beta1 to apps/v1

User facing changes

n/a

Before

n/a

After

n/a

Next PRs.

n/a

Submitter Checklist

These are the criteria that every PR should meet, please check them off as you
review them:

• Includes unit tests
• Mentions any output changes.
• Adds documentation as needed: user docs, YAML reference, CLI reference.
• Adds integration tests if needed.

Reviewer Notes

• The code flow looks good.
• Unit test added.
• User facing changes look good.

Release Notes

[codecov]

Codecov Report

Merging #3572 into master will not change coverage.
The diff coverage is n/a.

[dgageot]

Thanks a lot @oke-py! I had not realised we still had those around.