Deprecation warning when built manually with sass

[timobrembeck]

I build flagpack manually with sass, and since version 1.33.0, I get a few deprecation warnings:

"Using / for division is deprecated and will be removed in Dart Sass 2.0.0"

https://sass-lang.com/documentation/breaking-changes/slash-div

DEPRECATION WARNINGS

DEPRECATION WARNING: Using / for division is deprecated and will be removed in Dart Sass 2.0.0.

Recommendation: math.div(4, 3)

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

  ╷
6 │     width: (4 / 3) * $size;
  │             ^^^^^
  ╵
    node_modules/flagpack/src/_mixins.scss 6:13  fp-size()
    node_modules/flagpack/src/flagpack.scss 8:5  @import
    src/frontend/css/style.scss 5:9              root stylesheet

DEPRECATION WARNING: Using / for division is deprecated and will be removed in Dart Sass 2.0.0.

Recommendation: math.div($fp-size, 6)

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

   ╷
19 │       @include fp-rounded($fp-size / 6);
   │                           ^^^^^^^^^^^^
   ╵
    node_modules/flagpack/src/flagpack.scss 19:27  @import
    src/frontend/css/style.scss 5:9                root stylesheet

DEPRECATION WARNING: Using / for division is deprecated and will be removed in Dart Sass 2.0.0.

Recommendation: math.div($fp-size, 4)

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

   ╷
38 │           @include fp-rounded($fp-size / 4);
   │                               ^^^^^^^^^^^^
   ╵
    node_modules/flagpack/src/flagpack.scss 38:31  @import
    src/frontend/css/style.scss 5:9                root stylesheet

DEPRECATION WARNING: Using / for division is deprecated and will be removed in Dart Sass 2.0.0.

Recommendation: math.div($fp-size, 4)

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

   ╷
59 │           @include fp-rounded($fp-size / 4);
   │                               ^^^^^^^^^^^^
   ╵
    node_modules/flagpack/src/flagpack.scss 59:31  @import
    src/frontend/css/style.scss 5:9                root stylesheet

Since node-sass is deprecated in favor of dart-sass, I think flagpack should adapt its syntax here.