Deprecation warnings when building assets

[acicovic]

Describe the bug

We're getting deprecation warnings like Deprecation The legacy JS API is deprecated and will be removed in Dart Sass 2.0.0. when building our assets. This isn't a real problem yet, as assets still get build normally.

To Reproduce

Build the project's assets. The warnings will appear.

Expected behavior

We shouldn't be getting warnings.

Additional context

This seems to be an upstream issue, tracked here (also see here). If this was to be included in a future update of @wordpress/scripts though, we're currently stuck on an old version due to #2624.

[acicovic]

Related to #2608, as a general improvement to asset building.