CI: Migrate validators from deprecated Guardrails Hub to public PyPI in github workflow

[Prajna1999]

Fix: Migrate validators from deprecated Guardrails Hub to public PyPI

Problem

Guardrails has deprecated:

• Private registry: pypi.guardrailsai.com (shut down)
• Remote inference API: hub.api.guardrailsai.com (shut down)

Current CI fails because:

1. guardrails hub install <validator> commands no longer work
2. Validators that relied on remote model inference cannot execute
3. Any dependency on the private registry breaks the build

Solution

Migrate to public PyPI packages and local validator execution.

Changes required

1. Update GitHub Actions workflow

Before:

- name: Install validators
  run: guardrails hub install my-validator

After:

- name: Install validators
  run: pip install guardrails-ai-my-validator

Blockers

• Identify all validators currently in use
• Check which rely on remote inference (require migration plan)
• Test local model loading in CI environment