Problem/Motivation
As the batch API uses an animation and WCAG 2.1 introduces Success Criterion 2.2.9 Animation from Interactions (level AAA), it should be possible to disable the animation on the progress bar element.
Proposed resolution
Add a prefers-reduced-motion: reduce media query to disable the animation (i.e. respecting user prefs at the OS/browser level).
User interface changes
The animations will be disabled if requested by the user.