Fix compatibility with Dart Sass 3.0.0

[mir-jalu]

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

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

   ╷
35 │     @if function-exists(font-url) {

[markvantilburg]

@ahmadalfy can you merge this one

[ahmadalfy]

I think this is a breaking change. We can release it with the planned jQuery 4 release.

[joeda1]

libsass 3.0 was released oct 2014, and sass dart is not 3.x yet.
According the docs, meta is supported since (dart)sass 1.23
https://www.sasscss.com/documentation/modules/meta

That was 8 Years ago, time is going fast :)
https://github.com/sass/dart-sass/releases/tag/1.23.0