fix(editor): Migrate from @import to @use for SCSS files to address deprecation warnings (#17858)

packages/frontend/editor-ui/src/styles/index.scss

@@ -1,4 +1,4 @@
-@import 'variables';
-@import 'plugins';
-@import 'global';
-@import 'animations';
+@use 'variables';
+@use 'plugins';
+@use 'global';
+@use 'animations';

packages/frontend/editor-ui/src/styles/plugins/_vueflow.scss

@@ -1,3 +1,5 @@
+@use '@n8n/design-system/css/mixins' as mixins;
+
 /**
  * Resizer
  */

packages/frontend/editor-ui/src/styles/plugins/index.scss

@@ -1,2 +1,2 @@
-@import 'codemirror';
-@import 'vueflow';
+@use 'codemirror';
+@use 'vueflow';