Deprecate api_call action in Habitica integration

[tr4nt0r]

Proposed change

The action habitica.api_call is a generic action to poll the Habitica API. It is not user friendly at all, requires knowledge of the API endpoints and does not catch most exceptions, resulting in unknown error responses in the frontend.

A new action and several button and switch entities have been added recently and and to-do's and dailies have been migrated to the to-do platform. This should already cover the most common use cases for the habitica.api_call action, and there's still more in the pipeline:

• https://github.com/home-assistant/core/pull/127892
• https://github.com/home-assistant/core/pull/127687
• https://github.com/home-assistant/core/pull/126350

An issue will be created in case it is detected that the habitica.api_call action is used and a warning is logged.

Type of change

• [ ] Dependency upgrade
• [ ] Bugfix (non-breaking change which fixes an issue)
• [ ] New integration (thank you!)
• [ ] New feature (which adds functionality to an existing integration)
• [x] Deprecation (breaking change to happen in the future)
• [ ] Breaking change (fix/feature causing existing functionality to break)
• [ ] Code quality improvements to existing code or addition of tests

Additional information

• This PR fixes or closes issue: fixes #
• This PR is related to issue:
• Link to documentation pull request: https://github.com/home-assistant/home-assistant.io/pull/35232

Checklist

• [x] The code change is tested and works locally.
• [x] Local tests pass. Your PR cannot be merged unless tests pass
• [x] There is no commented out code in this PR.
• [x] I have followed the development checklist
• [x] I have followed the perfect PR recommendations
• [x] The code has been formatted using Ruff (ruff format homeassistant tests)
• [ ] Tests have been added to verify that the new code works.

If user exposed functionality or configuration variables are added/changed:

• [x] Documentation added/updated for www.home-assistant.io

If the code communicates with devices, web services, or third-party tools:

• [ ] The manifest file has all fields filled out correctly.
  Updated and included derived files by running: python3 -m script.hassfest.
• [ ] New or updated dependencies have been added to requirements_all.txt.
  Updated by running python3 -m script.gen_requirements_all.
• [ ] For the updated dependencies - a link to the changelog, or at minimum a diff between library versions is added to the PR description.

To help with the load of incoming pull requests:

• [ ] I have reviewed two other open pull requests in this repository.