CI should be switched from ansible-network/github_actions to ansible/ansible-content-actions

[yurnov]

SUMMARY

Currently a unified test framework is supported under ansible/ansible-content-actions
. So, it will be nice to replace the current CI ansible/ansible-content-actions and current documentation build process from collection_prep to antsibull-docs

ISSUE TYPE

• Feature Idea
• CI

COMPONENT NAME

CI/GitHub Actions

ADDITIONAL INFORMATION

That was suggested by @KB-perByte in #network:ansible.com matrix room when I looking for the review of my PR ansible-network/github_actions#156