When a contributor opens their first pull request to `wordpress-develop`, the “Welcome” workflow runs and leaves a comment with guidance, helpful information, and resources.
However, because a workflow run triggered by the `pull_request` event runs against the workflow and code from the merge commit, the needed context and permissions to comment on the pull request are missing. By changing the trigger event to `pull_request_target`, the workflow runs against the workflow and code in the base of the pull request and is able to comment on when appropriate.
See #50401.
git-svn-id: https://develop.svn.wordpress.org/trunk@49169 602fd350-edb4-49c9-b593-d223f7449a82
01e62f0cc3