Fix deprecated usage of set-output

[GaryGSC]

Refs: https://github.blog/changelog/2022-10-11-github-actions-deprecating-save-state-and-set-output-commands/

[github-actions]

Terraform Plan:

will create 1 resource:

• local_file - appspec_json

will replace (delete then create) 1 resource:

• aws_ecs_task_definition - task_def

see details