chore: Only run freeze reminder on internal repo

[nschonni]

Why:

Shouldn't affect forks or the public repo, but I'm guessing this will start triggering double notifications running on the public and private repo on the same cron schedule. The env.FREEZE check could probably be hoisted here too

What's being changed:

Check off the following:

• All of the tests are passing.
• I have reviewed my changes in staging.
• For content changes, I have reviewed the localization checklist
• For content changes, I have reviewed the Content style guide for GitHub Docs.

[heiskr]

Thanks! 🚢

[github-actions]

Thanks very much for contributing! Your pull request has been merged 🎉 You should see your changes appear on the site in approximately 24 hours.

[JamesMGreene]

I appreciate the critical eye and the contribution! 🙇🏻‍♂️ 💝

FWIW, I intentionally left this out when I created it to ensure we remembered to unfreeze both repos when the time came. We can try it this way and hopefully it works out as well. 😅

[nschonni]

@JamesMGreene fair enough, I figured it would more be noise in the slack channel, but feel free to revert as I can see it might catch only clearing the variable in one repo :)