Strip out SASS

[epugh]

Description

sassc-rails and sass-rails are abandoned. Dart Sass is the future. However, digging into it, we don't actually embrace sass, everything we do is just css...

Let's remove the Sass as much as possible.

One thing is that for some reason sprockets-rails and sprockets autoloads sassc, so we can't totally remove the dependency.

Motivation and Context

How Has This Been Tested?

Screenshots or GIFs (if appropriate):

Types of changes

• [] Bug fix (non-breaking change which fixes an issue)
• [] Improvement (non-breaking change which improves existing functionality)
• [] New feature (non-breaking change which adds new functionality)
• [] Breaking change (fix or feature that would cause existing functionality to change)

Checklist:

• [] My code follows the code style of this project.
• [] My change requires a change to the documentation.
• [] I have updated the documentation accordingly.
• [] I have read the CONTRIBUTING document.
• [] I have added tests to cover my changes.
• [] All new and existing tests passed.

[epugh]

I think I am done... So, Sprockets 4 will always invoke sassc, and so if you don't have it, you get an exception. So we are stuck with that. Also, Mission Control Jobs 0.6.0 still embeds sass, and of course, it doesn't work with latest sassc, only with dartsass. And Sprockets4 doesn't support dartsass... so kind of at an impass.. I think to move forward, we need to embrace jssbundling/cssbundling, or fork sprockets 4?