ci: use reusable vars HUB_BASE and IMAGE_LOCATION in workflow

[UsernameAlvarez]

This update modifies the GitHub Actions workflow to reference reusable
variables defined in the repository settings: HUB_BASE and IMAGE_LOCATION.

By doing this:

• We avoid hardcoding Docker image information.
• It improves maintainability and reusability across environments.
• Any future changes to these values can be done from GitHub UI
  without modifying the workflow files directly.

These vars are accessed using ${{ vars.HUB_BASE }} and ${{ vars.IMAGE_LOCATION }}
in the workflow YAML.

No logic or execution behavior is changed—only the configuration source.

[UsernameAlvarez]

/deploy

[UsernameAlvarez]

/deploy