chore(webapp): update sass

Update required for `vite@6`

Author: Rotzbua

www/webapp/package.json

@@ -33,7 +33,7 @@
     "eslint-plugin-vue": "^9.15.1",
     "eslint-plugin-vue-scoped-css": "^2.6.1",
     "eslint-plugin-vuetify": "^1.1.0",
-    "sass": "~1.32.13",
+    "sass": "~1.83.4",
     "unplugin-vue-components": "^28.0.0",
     "vite": "^6.0.11",
     "vuetify-loader": "~1.9.1"

www/webapp/vite.config.js

@@ -10,6 +10,15 @@ export default defineConfig({
     define: {
         'process.env.BUILD': '"web"' // fix for vuelidate@0.7.7
     },
+    css: {
+        preprocessorOptions: {
+            sass: {
+                api: 'modern-compiler',
+                /** @type {import('sass').Options.silenceDeprecations } */
+                silenceDeprecations: ['global-builtin', 'import', 'slash-div'],
+            },
+        },
+    },
     plugins: [
         vue({
             template: {