Resizing images in CP throws error: Assignment to constant variable.

[benfeather]

Describe the bug

When I try to resize an image that has already been uploaded to Craft (either through Settings > Image Resizer > Resize Bulk or through the assets section) I get an error logged to the browser console:

This site is using Craft cms' official Google Cloud Storage adapter.

Steps to reproduce

1. Go to Settings > Image Resizer > Resize Bulk
2. Click Bulk Resize next to and image folder (with the dev tools open)

Craft CMS version

5.4.2

Plugin version

4.0.1

Multi-site?

Yes

Additional context

No response

[engram-design]

Fixed for the next release. To get this early, run composer require verbb/image-resizer:"dev-craft-5 as 4.0.1".