fix: improve robustness of action

[FilippoBau]

Description

This Pull Request updates the PR title validation workflow to align with current GitHub Actions best practices.

Motivation and Context

It improves how inputs are passed to scripts and applies the principle of least privilege to the GitHub token for better overall repository hygiene.

List of changes proposed in this pull request

How Has This Been Tested?

Screenshots (if appropriate):

Types of changes

• Chore (nothing changes by a user perspective)
• 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 not work as expected)

Checklist:

• My change requires a change to the documentation.
• I have updated the documentation accordingly.