feat: add optional Galaxy server auth inputs to sanity, unit, and integration workflows

[djdanielsson]

Summary

• Adds three optional parameters (galaxy_server_url, galaxy_server_auth_url inputs and galaxy_server_token secret) to the sanity, unit, and integration reusable workflows.
• When galaxy_server_url is provided, ANSIBLE_GALAXY_SERVER_LIST is set to certified,galaxy and the corresponding ANSIBLE_GALAXY_SERVER_CERTIFIED_URL, _TOKEN, and _AUTH_URL env vars are populated on the tox run step. No temporary files are created.
• All parameters are optional and fully backward-compatible — callers that don't pass them see no change in behavior.

Motivation

Collections that depend on certified content hosted on Automation Hub (or other private Galaxy servers) currently cannot use these reusable workflows because ansible-galaxy / ade install fails to resolve dependencies that require authentication. This forces downstream repos to inline the entire sanity/unit/integration workflow just to inject authentication.

With this change, callers can simply pass the server URL and token:

jobs:
  sanity:
    uses: ansible/ansible-content-actions/.github/workflows/sanity.yaml@main
    with:
      galaxy_server_url: https://console.redhat.com/api/automation-hub/content/published/
      galaxy_server_auth_url: https://sso.redhat.com/auth/realms/redhat-external/protocol/openid-connect/token
    secrets:
      galaxy_server_token: ${{ secrets.AH_TOKEN }}

Test plan

• Verify existing callers that don't pass the new inputs continue to work unchanged (empty env vars are harmless)
• Confirm no temporary files are created or left behind

Made-with: Cursor