Add support for optional workload identity in preview deployments

[neel-astro]

Description:

With the upcoming CLI change to allow workload identity as part astro deployment inspect command, this would allow deploy action to extend the same feature for preview deployments, i.e. preview deployments picking up the workload identity from parent/base deployment. This should be an option in the deploy-action with default to false to not break existing logic, and only available if relevant CLI version is used.