[workflows] Avoid usage of access token in issue-write.yml (#94011)
This adds a new composite workflow that allows you to download artifacts
from other workflows without using an access token.
actions/download-artifact from GitHub requires an access token in order
to download artifacts from a different workflow, which is why we can't
use it here if we want to avoid using a token.
See
https://github.com/actions/download-artifact?tab=readme-ov-file#download-artifacts-from-other-workflow-runs-or-repositories