Add image release GitHub Actions

[kitsuya0828]

Description

Added GitHub Actions workflow to release image on GitHub Container Registry.

references:
https://github.com/docker/login-action
https://github.com/docker/build-push-action
https://github.com/kitagry/berglas-secret-controller/blob/main/.github/workflows/release.yaml

Motivation and Context

How has this been tested?

Screenshots (if appropriate):

Types of changes

• Bug fix (non-breaking change which fixes an issue)
• New feature (non-breaking change which adds functionality)
• Breaking change (fix or feature that would cause existing functionality to not work as expected)

Checklist:

• My code follows the code style of this project.
• My change requires a change to the documentation.
• I have updated the documentation accordingly.
• I have added tests to cover my changes.
• All new and existing tests passed.

[yokomotod]

LGTM!