Remove Sass deprecate code

[marcop135]

Deprecation Warning [global-builtin]: Global built-in functions are deprecated and will be removed in Dart Sass 3.0.0.
Use color.adjust instead.

More info and automated migrator: https://sass-lang.com/d/import

  ╷
8 │   background-color: darken($gray-light-extra, 5%);
  │                     ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^
  ╵
    src\assets\scss\pages\work\_projects.scss 8:21  @import
    src\assets\scss\main.scss 47:9                  root stylesheet