Update to dart-sass

Fixes #11335

Signed-off-by: Matt Stratton <[email protected]>

Author: mattstratton

gulp/tasks/dev/sass.js

@@ -1,13 +1,11 @@
 var gulp = require('gulp'),
-  sass = require('gulp-sass')(require('node-sass')),
+  sass = require('gulp-sass')(require('sass')),
   sourcemaps = require('gulp-sourcemaps');
 
-sass.compiler = require('node-sass');
-
 gulp.task('sass', function () {
     return gulp.src('themes/devopsdays-theme/static/scss/site.scss')
         .pipe(sourcemaps.init())
-        .pipe(sass({ style: 'compressed' }).on('error', sass.logError))
+        .pipe(sass.sync({ style: 'compressed' }).on('error', sass.logError))
         .pipe(sourcemaps.write('./'))
         .pipe(gulp.dest('themes/devopsdays-theme/static/css'));
   });