Background pages for Safari Web Extensions appears to be unable to load a local bundle resource to create a Web Worker script, even when the script is included in the web_accessible_resources in the manifest, as well as the worker-src in the content_security_policy.
I have no problem doing so on the other web extension platforms (Chrome, Firefox) with the same extension and code.
I've already filed a bug for this FB11955055, wondering if anyone else has been faced with this problem. It seems similar in nature to this issue https://stackoverflow.com/questions/73399285/safari-extension-background-page-unable-to-fetch-web-accessible-resource, but that one Apple claims to have resolved in Safari 16.
Edit: added error message