extract warnings in GH workflows
# What does this PR do?

This PR uses the change in #20474 to collect the warnings in our GH scheduled daily CI, and provide a button in the slack reports to access this information.

<img width="493" alt="image" src="https://user-images.githubusercontent.com/2521628/204501762-1ed46a7c-4a91-40ba-9b16-3288168f0dfc.png">

_The documentation is not available anymore as the PR was closed or merged._