chore: upgrade to tailwind v4 (#18353)

web/vite.config.js

@@ -1,5 +1,6 @@
 import { enhancedImages } from '@sveltejs/enhanced-img';
 import { sveltekit } from '@sveltejs/kit/vite';
+import tailwindcss from '@tailwindcss/vite';
 import { svelteTesting } from '@testing-library/svelte/vite';
 import path from 'node:path';
 import { visualizer } from 'rollup-plugin-visualizer';
@@ -36,6 +37,7 @@ export default defineConfig({
   },
   plugins: [
     enhancedImages(),
+    tailwindcss(),
     sveltekit(),
     process.env.BUILD_STATS === 'true'
       ? visualizer({