updated tf validate workflow to latest version of actions

[douglas-f]

Pull Request Checklist

Take your time to read through these, don't just click through them. Only check the boxes if they apply.

Admin

• Required: I have read the contributing guidelines for submitting a PR.

Types of changes

• 🐛 Bug fix (non-breaking change which fixes an issue)
• ❇️ New feature (non-breaking change which adds functionality)
• 💥 Breaking change (fix or feature that would cause existing functionality to change)

Testing

• Required: I have tested the proposed changes to code (i.e. packer build, terraform apply), and they are working.
• Required: All GitHub Actions ran successfully. If they didn't, I left a note in the description to address this.
• Optional: I have already applied/deployed the changes in my environment.

Please check where this code has been tested:

• Locally
• Customer Environment
• Coalfire Sandbox Environment (AWS GovCloud, Azure Gov, GCP, etc.)

Documentation

• Optional, recommended: I have updated README.md.
• Optional, recommended: I have updated documentation in Confluence/Organization's relevant Wiki.
• Optional, recommended: I left comments in-line in the code to help others understand the changes.

Tagging / Assigning

• Required: I have tagged a Reviewer(s).
• Required: I have tagged an Assignee(s).
• Optional: I have tagged relevant stakeholders in a Comment.