Modernize GitHub Actions workflows

[tysoncung]

Summary

This PR updates the GitHub Actions workflows to use modern, supported versions and fixes a syntax error.

Changes

• Update actions/checkout from v1 to v4 in multiple workflows (actions.yml, env.yml, container.yml)
• Fix Python print statement syntax error in simple.yml

Motivation

• actions/checkout@v1 is very outdated and should be updated to v4 for security and compatibility
• The Python code had a syntax error with the print statement split across lines
• These updates ensure the workflows will continue working with current GitHub Actions standards

Testing

The updated workflows should run successfully on this PR to verify the changes work correctly.

[tysoncung]

Hi @alialaa, friendly follow-up on this PR! Updates the GitHub Actions to v4 and fixes a Python syntax error. The changes are minimal and improve security/compatibility. Let me know if you need anything else. Thanks!