Node12 has been out of support since April 2022. As a result we started the deprecation process of Node12 for GitHub Actions by migrating all actions to run on Node16 on June 14th.
We have seen no major issues reported and a minimal number of people opted out of the forced upgrade to Node16. Given this, we will remove Node12 from the Actions runner on the 14th of August 2023.

What you need to do

For Actions maintainers: Update your actions to run on Node16 instead of Node12 (Actions configuration settings)
For Actions users: Update your workflows with latest versions of the actions which runs on Node16 (Using versions for Actions)