(maint) Add stale.yml file sync

[pauby]

Description Of Changes

Adds file syncing of stale.yml file for the GitHub workflow.

Motivation and Context

We need a consistent policy for managing stale issues across our repositories.

Testing

This is currently working in chocolatey/choco repository and the file is a copy from there.

Operating Systems Testing

N/A

Change Types Made

• Bug fix (non-breaking change).
• Feature / Enhancement (non-breaking change).
• Breaking change (fix or feature that could cause existing functionality to change).
• Documentation changes.
• PowerShell code changes.

Change Checklist

• Requires a change to the documentation.
• Documentation has been updated.
• Tests to cover my changes, have been added.
• All new and existing tests passed?
• PowerShell code changes: PowerShell v2 compatibility checked?

Related Issue

N/A