Sass Deprecation warnings during build process with v 1.80.x

[MattyRob]

Follow up to #62142

SASS has deprecated global functions and also the @import rule, see here:

​https://sass-lang.com/documentation/breaking-changes/import/
​https://sass-lang.com/documentation/at-rules/import/

Fixes for this have been created in a PR for ClassicPress and we are sharing this back should you wish to consider the same solution.

Patch files for the 2 commits are attached and the original PR is here:

​https://github.com/ClassicPress/ClassicPress/pull/1621

Trac ticket: https://core.trac.wordpress.org/ticket/62323

[desrosj]

Thanks for this, @MattyRob!

The patch did not apply correctly, but I went ahead and created the attached PR to test it out.
DEPRECATION WARNING [user-authored]: The legacy JS API is deprecated and will be removed in Dart Sass 2.0.0.

There are still several of these warnings, but I think this is due to grunt-sass not yet accounting for the changes upstream. There is an ​open issue and even ​a fork with the fix published as grunt-sass-modern.

I double checked the built files, and no unexpected CSS changes resulted. Will confirm after committing.

[desrosj]

In 59656:

Administration: Modernize admin color scheme SASS files.

This updates the admin color scheme .sass files to address some deprecated notices caused by upstream changes.

• string and colors are no longer globally available functions.
• @import is deprecated in favor of @use.

There are still a few notices that are output, however this will require an update to the grunt-sass package to resolve.

Props MattyRob.
Fixes #62323.

Merged in https://core.trac.wordpress.org/changeset/59656.

[desrosj]

Confirmed there are no changes to .css files after [59656]: ​https://build.trac.wordpress.org/changeset/58999.