PRs triggered by aria-practices falling out of sync

[howard-e]

This was recently observed in w3c/aria-practices#2622 (comment), where the following error was being surfaced:

Error:

/home/runner/work/wai-aria-practices/wai-aria-practices/scripts/pre-build/library/determineContentType.js:48
throw new Error(
^
Error: Could not determine content type for file at /home/runner/work/wai-aria-practices/wai-aria-practices/_external/aria-practices/content/about/introduction/introduction.html
This file may not follow established conventions.

The pr-create.yml seems to be missing a crucial step in ensuring the generated PR in this repository is rebased onto the default branch before regenerating the preview.

This hasn't been an issue in the past mainly because of the typically static and unrelated nature of the content and utilities. Also of assistance, was how GitHub's default updating of an existing PR works when the default branch is updated. But in this instance (and others), wai-aria-practices has undergone many changes which were not properly accounted for.

Exploring automatic rebases when the script runs (or exploring manual but assisted triggers such as actions/automatic-rebase) should be considered.

[howard-e]

Wiki page on how to manually fix for now