Output deprecated endpoints with deprecation annotations

[dadajam4]

Description

Currently, if an OpenAPI endpoint is marked as deprecated, it seems it won't be output as an endpoint in Aspida.
This is problematic because clients won't be able to call the API during gradual specification changes.

Describe the solution you'd like

It would be great to add an option to the Aspida generation settings that allows outputting configurations such as endpoints, even when marked as deprecated.

Describe alternatives you've considered

We'll refrain from setting deprecated flags on the application side. However, this isn't preferable for managing extensive API specification changes.

Additional context

I suspect that the implementation around the following areas is likely relevant.

openapi2aspida/src/buildV3.ts

Line 70 in 58696c3

if (target.deprecated) return null;