Remove old `deploy` command and `/deploy` API endpoint

[mpangrazzi]

With this we will deprecate remove:

• hayhooks pipeline deploy command
• /deploy API endpoint

and related legacy code used to create dynamic Pydantic models for request / response without a pipeline wrapper.

We can make hayhooks pipeline deploy command an alias of deploy-files and so we will do with /deploy / deploy-files API endpoint.

The README already explains that the above features are legacy and about to be deprecated.